Qt4 Application renders blank (white) windows under Ubuntu 12.04

[Kivin]

I've written a Qt application which runs correctly under Windows 7. When I build under linux and execute the application, what appears is a blank window. The title bar (including the window title, the X, minimize and maximize boxes) is visible, but the entire client area of the window is completely blank.

[Kivin]

After a "$make clean" and "$make", all my widgets are displaying correctly with the exclusion of the QMenuBar on my QMainWindow. The space it uses appears to be allocated, but blank (transparent, solid white, whatever).

[tobias.hunger]

Which Qt version are you using? The one shipped by ubuntu or something installed yourself?