Qt project will not build after upgrade to XCode 3.2.6

I have a project which was build using Qt 4.5.3 on Xcode 3.2.3. I have recently upgraded my XCode to 3.2.6 and now I cannot get the project to build. I get errors such as "QtCore/QtCore: No such file or directory" even though my headers and libraries are all setup correctly. I would like my project to build using the Mac OSX 10.6 base SDK and to use the LLVM GCC 4.2 compiler version. Could this be why things are no longer building? Do I need to recreate the Qt moc and ui files?
I'm at a loss as to why things aren't working. Any suggestions on what I could try would be greatly appreciated.

It seems that your headers are not setup correctly if xcode is complaining.

Clean whole solution, run qmake and build the project, if your headers are in fact seen correctly then the project should build.