Comment 1 for bug 144758

Yeah, this problem really annoyed me too. It turns out to be a symptom of the way Gutsy starts Xgl. A hack workaround is to replace /usr/share/xserver-xgl/Xgl-session with the "old recommended way" of starting Xgl:

#!/bin/bash
Xgl -fullscreen :1 -ac -br -accel glx:pbuffer -accel xv:fbo +xinerama & sleep 2
DISPLAY=:1
cookie="$(xauth -i nextract - :0 | cut -d ' ' -f 9)"
xauth -i add :1 . "$cookie"
exec dbus-launch --exit-with-session gnome-session

Actually I just pasted the above at the beginning followed by "exit 0" so that when someone tells us the right way to do it, I can easily rip my hack out. The official version of Xgl-session seems to offer some nice protections in case of an X server crash.