I know you want it to do a certain speed, and do it now, but take it slow and in steps. It can be a PITA when you want to just crank it and have it run, but it's well worth it. Drop down to a slower speed, perhaps 2.3Ghz @ 1.65v, and see how that goes. It's even possible the problem isn't the CPU @ all, but something else...perhaps memory.
