His other thread on the same subject came to the same conclusion. Re-install may be the only answer, may be a bug in the OS or a program you have added that does not conform to Microsofts rules and has cocked up the OS.
ha! i got it!
i was looking through the asus forums trying to figure out how to fix my bsods that only appear during loading screens of games, and i stumbled upon a thread that had millions and millions of people with the same problem as me!... ok maybe not millions but lots!
turns out asus gamer OSD stuffs up aero! (on 4850 and windows 7 atleast)
unistall, restart and then BAM! its back!
now i just gotta get used to it again haha!