Originally Posted by Senor Hubris
Okay, I looked at your bug report and it shows you are using 9631. I don't recall, but I believe that version had the XV issue also (which is why I don't use the driver that Ubuntu installs. Instead I compile my own). You should try a more recent driver.
I tried installing my own driver in Ubuntu and I didn't have much luck. It compiled and "installed" but then when it rebooted the X server was pissed saying that it couldn't find some files. I can't remember exactly what it was at the time, but I couldn't get it fixed until I re-installed Ubuntu flat out.