Comment 4 for bug 174899

I too have encountered this same error.

I have been unable to reliably recreate this bug, but it happens every so often, and seems to be related to video playback. In two occasions I saw the bug happen. The first was when switching workspaces with a video playing in VLC in one workspace and evolution in another. I switched away from the movie, worked in evolution for a short time, then switched back. The video's workspace did not appear, and in its place a fullscreen multi-color static display for a few seconds, then GDM restarts and I can log back in. The second time I encountered this bug was while starting a movie through the mozilla-mplayer plugin. The movie finished caching and Xorg displayed the multi-color static field and restarted.

I have compiz/compiz fusion disabled if it makes any difference.

Fully updated as of Dec 12th.