E6420 OC on asus p5n-d

Shit sucks...

E6420 stock 2.13Ghz target 3.2ghz currently at 2.8 stable.
Intel Stock air cooling with AS5, I'm cheap bastard.
Asus P5N-D mobo
Corsair memory at 800mhz 5-5-5-12 -2T
Enermax 500w PSU
EVGA Gtx260 Core 216

Basically I hit a wall at 3ghz @ 1.49v, it's not stable but if I back down a bit to 2.8 or 2.9ghz and drop the volts to 1.45v everything is good and stable, or I think, I've only been doing 30min prime95 test.

I'm trying to hit 3.2ghz and I have booted but barely got past the memory check.

I've played with the NB volts 1.3-1.6v and this HT voltage 1.3-1.6v which I have no idea what it does except remind me of hyper-threading, they seem to have some marginal effect but not as much and SB is useless won't post if I raise the volts to 1.6v.

So the question is...
memory or board?

Maybe cpu?

is this my wall?

I vote cooler, maybe?

Aren't the stock Core 2 Duo coolers tiny? I suggest Cooler Master Hyper TX3 or Cooler Master Hyper 212+. Super cheap coolers. I'll be getting one when budget permits ^.^