https://bugs.freedesktop.org/show_bug.cgi?id=42678
--- Comment #11 from Michel Dänzer michel@daenzer.net 2011-11-08 02:33:27 PST --- If none of Alex's suggestions help, does either of the following options work around the problem?
Option "SwapbuffersWait" "off" Option "EnablePageFlip" "off"