diff --git a/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv3TradeBot.java
index 9033e717..9ab97be9 100644
--- a/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv3TradeBot.java
@@ -19,6 +19,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -317,20 +318,36 @@ public class BitcoinACCTv3TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
@@ -548,15 +565,25 @@ public class BitcoinACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -668,15 +695,25 @@ public class BitcoinACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/DigibyteACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/DigibyteACCTv3TradeBot.java
index 171e818b..4b1ba7bb 100644
--- a/src/main/java/org/qortal/controller/tradebot/DigibyteACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/DigibyteACCTv3TradeBot.java
@@ -19,6 +19,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -317,20 +318,36 @@ public class DigibyteACCTv3TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
@@ -548,15 +565,25 @@ public class DigibyteACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -668,15 +695,25 @@ public class DigibyteACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv1TradeBot.java b/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv1TradeBot.java
index d37a6650..52e7bb24 100644
--- a/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv1TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv1TradeBot.java
@@ -19,6 +19,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -317,20 +318,36 @@ public class DogecoinACCTv1TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
@@ -548,15 +565,25 @@ public class DogecoinACCTv1TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -668,15 +695,25 @@ public class DogecoinACCTv1TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv3TradeBot.java
index 996097f3..b57b9354 100644
--- a/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/DogecoinACCTv3TradeBot.java
@@ -19,6 +19,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -317,20 +318,36 @@ public class DogecoinACCTv3TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
@@ -548,15 +565,25 @@ public class DogecoinACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -668,15 +695,25 @@ public class DogecoinACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv3TradeBot.java
index a4ae921e..b5631f0b 100644
--- a/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv3TradeBot.java
@@ -325,15 +325,24 @@ public class LitecoinACCTv3TradeBot implements AcctTradeBot {
 					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
 					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 					messageTransaction.sign(sender);
 
 					// reset repository state to prevent deadlock
 					threadsRepository.discardChanges();
-					ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-					if (result != ValidationResult.OK) {
-						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
 					}
 				} catch (DataException e) {
 					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
@@ -556,15 +565,25 @@ public class LitecoinACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -676,15 +695,25 @@ public class LitecoinACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/PirateChainACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/PirateChainACCTv3TradeBot.java
index 9834df20..4b5126d9 100644
--- a/src/main/java/org/qortal/controller/tradebot/PirateChainACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/PirateChainACCTv3TradeBot.java
@@ -20,6 +20,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -320,20 +321,36 @@ public class PirateChainACCTv3TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddressT3));
@@ -561,15 +578,25 @@ public class PirateChainACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -681,15 +708,25 @@ public class PirateChainACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/main/java/org/qortal/controller/tradebot/RavencoinACCTv3TradeBot.java b/src/main/java/org/qortal/controller/tradebot/RavencoinACCTv3TradeBot.java
index 80fe7932..ed71d0e3 100644
--- a/src/main/java/org/qortal/controller/tradebot/RavencoinACCTv3TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/RavencoinACCTv3TradeBot.java
@@ -19,6 +19,7 @@ import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.group.Group;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.MessageTransaction;
 import org.qortal.transaction.Transaction.ValidationResult;
@@ -317,20 +318,36 @@ public class RavencoinACCTv3TradeBot implements AcctTradeBot {
 
 		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
 		if (!isMessageAlreadySent) {
-			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+			// Do this in a new thread so caller doesn't have to wait for computeNonce()
+			// In the unlikely event that the transaction doesn't validate then the buy won't happen and eventually Alice's AT will be refunded
+			new Thread(() -> {
+				try (final Repository threadsRepository = RepositoryManager.getRepository()) {
+					PrivateKeyAccount sender = new PrivateKeyAccount(threadsRepository, tradeBotData.getTradePrivateKey());
+					MessageTransaction messageTransaction = MessageTransaction.build(threadsRepository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
-			messageTransaction.computeNonce();
-			messageTransaction.sign(sender);
+					LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
+					messageTransaction.computeNonce();
+					MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+					LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
+					messageTransaction.sign(sender);
 
-			// reset repository state to prevent deadlock
-			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
+					// reset repository state to prevent deadlock
+					threadsRepository.discardChanges();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
-				return ResponseResult.NETWORK_ISSUE;
-			}
+					if (messageTransaction.isSignatureValid()) {
+						ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+						if (result != ValidationResult.OK) {
+							LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+						}
+					}
+					else {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: signature invalid", messageRecipient));
+					}
+				} catch (DataException e) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, e.getMessage()));
+				}
+			}, "TradeBot response").start();
 		}
 
 		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
@@ -548,15 +565,25 @@ public class RavencoinACCTv3TradeBot implements AcctTradeBot {
 				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
 
+				LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", outgoingMessageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 				outgoingMessageTransaction.computeNonce();
+				MessageTransactionData newMessageTransactionData = (MessageTransactionData) outgoingMessageTransaction.getTransactionData();
+				LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), outgoingMessageTransaction.getPoWDifficulty());
 				outgoingMessageTransaction.sign(sender);
 
 				// reset repository state to prevent deadlock
 				repository.discardChanges();
-				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
 
-				if (result != ValidationResult.OK) {
-					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				if (outgoingMessageTransaction.isSignatureValid()) {
+					ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+					if (result != ValidationResult.OK) {
+						LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+						return;
+					}
+				}
+				else {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 					return;
 				}
 			}
@@ -668,15 +695,25 @@ public class RavencoinACCTv3TradeBot implements AcctTradeBot {
 			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
 			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
 
+			LOGGER.info("Computing nonce at difficulty {} for AT {} and recipient {}", messageTransaction.getPoWDifficulty(), tradeBotData.getAtAddress(), messageRecipient);
 			messageTransaction.computeNonce();
+			MessageTransactionData newMessageTransactionData = (MessageTransactionData) messageTransaction.getTransactionData();
+			LOGGER.info("Computed nonce {} at difficulty {}", newMessageTransactionData.getNonce(), messageTransaction.getPoWDifficulty());
 			messageTransaction.sign(sender);
 
 			// Reset repository state to prevent deadlock
 			repository.discardChanges();
-			ValidationResult result = messageTransaction.importAsUnconfirmed();
 
-			if (result != ValidationResult.OK) {
-				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+			if (messageTransaction.isSignatureValid()) {
+				ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+			else {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: signature invalid", messageRecipient));
 				return;
 			}
 		}
diff --git a/src/test/java/org/qortal/test/MessageTests.java b/src/test/java/org/qortal/test/MessageTests.java
index 3e549235..c76c715e 100644
--- a/src/test/java/org/qortal/test/MessageTests.java
+++ b/src/test/java/org/qortal/test/MessageTests.java
@@ -29,6 +29,7 @@ import org.qortal.utils.NTP;
 
 import static org.junit.Assert.*;
 
+import java.util.List;
 import java.util.Random;
 
 public class MessageTests extends Common {
@@ -173,6 +174,10 @@ public class MessageTests extends Common {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
 
+			// Transaction should not be present in db yet
+			List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, recipient, null, null, null);
+			assertTrue(messageTransactionsData.isEmpty());
+
 			MessageTransaction transaction = testFeeNonce(repository, false, true, recipient, true);
 
 			// Transaction shouldn't be confirmable because it's not to an AT, and therefore shouldn't be present in a block
@@ -181,6 +186,10 @@ public class MessageTests extends Common {
 			assertFalse(isTransactionConfirmed(repository, transaction));
 			assertEquals(12, transaction.getPoWDifficulty());
 
+			// Transaction should be found when trade bot searches for it
+			messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, recipient, null, null, null);
+			assertEquals(1, messageTransactionsData.size());
+
 			BlockUtils.orphanLastBlock(repository);
 		}
 	}