Comment 2 for bug 145789

Had the same problem with my intel 915. Found the soulution here:

http://ubuntuforums.org/showpost.php?p=3416144&postcount=15

I just uninstalled the xserver-xgl package and then everything worked just fine. According to the post above this is not a bug, just a performance issue... But for the intel cards that xserver-xgl isn't working for it should be disabled by default...