COD4 Crashses

Hello I have 2 crossfire 4850's. Everytime I run either crysis or COD4 the game crashes at some point. Sometimes 5 minutes in sometimes 45 minutes in sometimes with a really high pitch noise and is usually at the loading screen with the little intel videos when it crashes in single player. Its a really annoying problem because I always have to hard reboot, I would really appreciate some help.
Thanks,
Zman

I have the same problem. Trying jacking up your fan speeds with Riva Tuner or whatever you use. Its not a great fix, but it will atleast let you play until we can figure out something.