It's been suggested this may be a duplicate of Bug #557829 however I think this bug appeared only after that one was reported.
People might also be interested in the 2nd post of: http://ubuntuforums.org/showthread.php?s=8674fdc2aaebd69745b39dd9f877ed8b&p=9146088 It suggests this bug may cause hardware damage and strongly suggests switching to fglrx in the meantime.
It's been suggested this may be a duplicate of Bug #557829 however I think this bug appeared only after that one was reported.
People might also be interested in the 2nd post of: http:// ubuntuforums. org/showthread. php?s=8674fdc2a aebd69745b39dd9 f877ed8b& p=9146088 It suggests this bug may cause hardware damage and strongly suggests switching to fglrx in the meantime.