dtgreene: Maybe your computer is overheating?
(If possible, try setting your computer's power settings to something like "power saving" mode, and see if that helps.)
Coming to think of it, my PC has had heat issues but only when running FPS games. When my laptop overheats, it simply turns itself off. I've never had a freeze with any game where the only way I could get out of it was by holding down the power button.
Whenever the crash occurred, I always had summons active so I assumed it was a bug regarding summons. When I start my second play through of EE, I'll be sure to check for over heating though.
Pangaea666: Your computer has become sentient, and is reacting the only way it knows how to such vile code being run through its circuits.
Lol, or it could be like Jerrod's stone. Sealing away the running code of evil before Belheifit pops his head out of my optical drive ;)