We screwed up! A serious bug in Qt 4.6.3's QtOpenGL module on Windows went undetected through reviewing, the auto-test system and quality assurance! The bug causes a device context leak, and after 9999 repaints, the program stops updating its widgets. The bug is fixed in our repositories and will not appear in our next releases. Until then, if you are compiling Qt from source, you can use the this patch.