Steps to reproduce with attached qrc_test example:
1. Open project in Visual Studio
3. Modify file1.
4. Compile (F7)
-> qrc_xxx.cpp is modified
5. Add file2 to qrc
6. Compile (F7)
7. Modify file2
8. Compile (F7)
-> qrc_xxx.cpp is not modified to reflect changes made to file2 because file2 dependency is not in *.vcxproj, only file 1 is. Even rebuilding the whole solution does not add file2 dependency to *.vcsproj -file.
As a workaround you can import *.pro file again to regenerate *.vcxproj after you have added file to qrc, or add dependensy otherwise ti *.vcxproj.