Comment 12 for bug 154104

Please note, I have more or less the same graphics setup (Dell Optiplex 520 with and identical problems. Since upgrading from Feisty to Gutsy I notice that window redraws were happening very slowly. Following all the above instructions leads to similar results with one exception: glxgears crashes the Xserver (nothing interesting in the Xorg.0.log file).

I tried deleting Xorg.conf and reconfiguring with dpkg-reconfigure in case something in old xorg.conf was causing it, but no joy.