I found what seems to be a temporary solution to the problem !
Reversing the package xserver-xorg-video-ati to the version 1:6.6.3-2ubuntu6 (from feisty, available here http://archive.ubuntu.com/ubuntu/pool/main/x/xserver-xorg-video-ati/ ) seems to fix the problem !
Been running it for 4 hours without a freeze so far, will keep posted if anything goes wrong.
I found what seems to be a temporary solution to the problem !
Reversing the package xserver- xorg-video- ati to the version 1:6.6.3-2ubuntu6 (from feisty, available here http:// archive. ubuntu. com/ubuntu/ pool/main/ x/xserver- xorg-video- ati/ ) seems to fix the problem !
Been running it for 4 hours without a freeze so far, will keep posted if anything goes wrong.