I installed both QT (4.6.3) and Code::Blocks (10.0.5) on Windows 7 (Home Premium).
I tried using the QT4 wizard, setting the QT folder to C:\Qt\2010.04\qt (your QT installation folder may be different).
When I try to build and run the project, it builds, but I get the runtime error message "The procedure entry point _Z13qFlagLocationPKc could not be located in the dynamic link ibrary QtCore4.dll."
I went to the Project > Build options and then the "Linker settings" tab and deleted the two entries (QtCore4 and QtGui4),
then cleaned the project (Build > Clean) and then built and ran the project and it worked fine.
I have not tried more complicated projects yet with Code::Blocks.