Comment 1 for bug 150092

Can you try the latest package from here (ubuntu1tv6):

http://ppa.launchpad.net/tormodvolden/ubuntu/pool/main/x/xserver-xorg-video-ati/

there is a new version (6.7.195) sitting in the queue, but due to the freeze (and weekend) it has not yet been accepted to the archive. I believe that version could fix this.