I've had the same problem. My work around was to drop to tty from the login prompt (clicking the login window corrupted and froze the system) and then remove the current nvidia drivers:
sudo apt-get purge nvidia-glx-* Install the latest: sudo apt-get install nvidia-glx-185 and then run nvidia xconfig nvidia-xconfig After a reboot everything worked. -- Corrupt graphics on boot with 7800GT/nv https://bugs.launchpad.net/bugs/62230 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nv in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp