FlyingBike,

Do NOT do this if you are still on AppleCare or Warranty this COULD nullify it. Jethro is CORRECT it is probably a bad THERMAL SENSOR as iFixit has suggested, I am having the same problem, but I will let the Apple Techies deal with it. I hate to wait for them guys to gulp down their coffee and jelly rolls; but I will wait to protect my warranty.

Just would NOT someone that is "adrift in the same boat as me" jump in and get eaten by the sharks!

Good Luck and Hope you get yours resolved quickly as well.