My mosfet's are hot to the touch @ 220 FSB, 2 120mm front and back in push pull, one 80mm blow hole blowing directly on them. It should be more of an issue at higher FSB speeds, but with phenom pushing 4 cores if they get to hot their going to cause stability problems. For that matter any cpu will tend to destabilize with the mosfet's running to hot.

Not to say that's the only problem, I'm positive lack of vcore is a big part. But it's some thing to look at.

I've been polling the high end over clockers I know and they all agree that on a value based board (especially under water) one of the top suspects in instability is excess mosfet heat.