The new forums will be named Coin Return (based on the most recent vote)! You can check on the status and timeline of the transition to the new forums here.
The Guiding Principles and New Rules document is now in effect.
I updated my drivers to the most recent ones, blew the dust out of the card (which helped, I can get more time before the error occurs) and opened the case up.
It seems like a heat issue, but it's only with M:TW 2. WoW runs fine, as did L4D and DoW2 recently.
The card if an nbvidia geforce 7800 GT.
I played Medieval 2 without problems when I first bought it, so this is something new.