Hi! I'm running Opensuse 13.1 with KDE of course, and when opengl 1, 2 or 3 is set for compositing instead of Xrender, when I switch display configuration (when I turn on one of my two displays for example), they both turn black but what is behind the "black layer" still runs (eg. if I had a video running before the switch it still runs and if I double-click it, it still comes fullscreen). I find it very annoying since I like to enable desktop effects that require Opengl to work properly. I have a NVIDIA card so I've the most stable and up-to-date version of the driver installed manually. Do you guys have some idea of what could cause that bug?

Ok, I found that pressing alt+F12 twice solved the problem. Topic solved!!!