Funny, I read of ppl having problems after installing the latest driver all the time.
Only downgrading or waiting for a newer driver fixes the prob.
Now, I don't care whether they are doing something wrong, fact is, this kind of trouble seems to be reserved for Radeon owners only.
(I think we even have some in this forum)
Concerning the 10.8: Wait for 10.9 to FU something else. lol