Comment 14 for bug 773564

Back on Maverick I experienced similar hangs related to vmware player, but back then I could ssh in and just kill the player to fix the problem.

I since switched to virtualbox and the hangs no longer occurred until I upgrated to Natty, and it does not appear to be linked to any particular program.
I've seen it happen with just a VirtualBox vm running, a Windows app in Wine, Pidgin, Lotus Notes etc.

Next time it happens I'll check for cpu usage instead of just restarting gdm