CCC

Sup /tech/.
I recently upgraded from an 8800 GTS to a 4850.
The 4850 works great, aside from Catalyst Control Center.
Attempting to open CCC causes all my monitors to go black and the fan on the card to ramp up 100%. After this point, I have to reboot.
I've tried uninstalling and reinstalling the drivers, but the issue persists.
The card works great in games.
I'm at a loss.
Yes, I was sure to totally remove all Nvidia drivers prior.

Back when I had an hd4870 I remember CCC wasn't even worth installing because of the issues it would create. For you it may be worth it to check CCC for fan control options and see if you can adjust the fan settings.