Here is an interesting thing I learned last night:

I have two OCs on my P2 that I have done roughly 3-hour prime sessions on: 3.6GHz 1.36v and 3.7GHz 1.39v. Both of these passed the prime with no issues whatsoever.

However, neither of those OCs could play FEAR2 multiplayer for more than an hour. Had to add more volts.

It's interesting that my chip will prime well at lower volts than it's actually "stable". Anyone else have similar results?