Version: (using Devel) Installed from: Compiled sources Just updated to r791114 and resizing windows horizontally gives interesting artefacts: When you make a window smaller by dragging the left border, the buttons (moximize, minimize, ...) aren't redrawn. When you make the window larger the buttons get drawn over and over again, but the old ones doesn't get removed. Looks a bit like resizing windows doesn't invalidate the window borders. If you need more information or want a screenshot: Tell me :)
Some more information: You can find a screenshot attached now. More or less the same happens with other window decorations than Oxygen, but they seem to be more robust. Making the window smaller is no problem for most of them e.g. I'm using and r300 with the radeon driver and composite is not used. When the "broken" window is no more avtive the window border is completely fine again.
Created attachment 24120 [details] Screenshot showing the problem.
Some more information coming directly from #debian-qt-kde: Nearly the same thing happens with KDE 4.0.2 and Qt 4.4, but the buttons also completely vanish, when making the window smaller. This means this is a Qt 4.4 beta1 bug. With 4.3 everything was fine. "QT_USE_NATIVE_WINDOWS=1 kwin --replace" makes the situation much better, but there are still some artefacts. The gradient of the boarder when using the Oxygen theme also doesn't change when you resize windows which means that only the part of the border where the buttons where get redrawn.
*** This bug has been marked as a duplicate of 157659 ***