I know that the new iMacs may have a freezing problem, but mine is one of the older ones - bought it a few months before the Intels came out. It's gotten alot of use, only about 20GB of memory left...but I've never had a problem like this with any of my macs. Computer will just freeze up on it's own and the fans will just be going! I mean it's asleep and it'll freeze. What gives?