Comment 5 for bug 137422

I came across this bug #136598, and followed this:

As someone stated in the forums ( http://ubuntuforums.org/showthread.php?t=540386 ), deleting this file and restarting will do the trick. At least for some of us.

sudo rm /etc/X11/Xsession.d/00xserver-xgl_start-server

So I removed that file to another location, and it works now. Everything works.