BUILD & INSTALL:
qmake
make
copy scim-panel-dbus <your dir which scim-panel-gtk lives in>

CONFIGURE:
edit your scim's global config file,
 ( it's /etc/scim/global in my box(Archlinux distro). )
change this line:

/DefaultPanelProgram = scim-panel-gtk

into:

/DefaultPanelProgram = scim-panel-dbus

reboot your system (or manually kill all scim related process)