Version: 4.3.0 (using KDE 4.3.0) Installed from: Ubuntu Packages I've noticed that sometimes some windows in my desktop would end up with some areas painted with portions of underlying windows or desktop wallpaper. Those paint artefacts would disappear after minimizing-maximizing the affected window. Then I noticed that those artefacts would only appear in the bottom part of the windows and only when they were near the panel. After a bit of digging I ended up not only discovering that that problem was caused by the panel's popup window, that somehow repaints the area of the previous popup window background when generating a new popup window and only when the popup window is triggered while avoiding the "from the previous popup to the newly created one" popup animation. As my panel is set to automatically hide, that is achieved by moving the cursor away from the panel and while it hides move the cursor and place it on top of another taskbar application button. That isn't a perfect way to trigger the bug, as sometimes it fails to replicate it.
Created attachment 36282 [details] artefacts screenshot Screenshot taken after generating the artefact from triggering the "vm séries" taskbar popup window and then triggering the "dissertações" taskbar popup window.
This is bug 194029 / bug 177959. Thanks *** This bug has been marked as a duplicate of bug 177959 ***
This is clearly a Xorg bug, I was able to write a xlib-only testcas (as I was asked for), but then nothing happend. If you want this bug fixed, please vote for it and make some polite noise at: https://bugs.freedesktop.org/show_bug.cgi?id=22566