Advice Needed on 4600+ Overclock

The core components are this:

Athlon X2 4600+ (non EE)
Asus M2N-SLI Deluxe
2GB Corsair XMS2 DDR2-800 @ 4-4-4-12, 2.1v

edit:
Other major specs:
Enermax Liberty 500W PSU
EVGA 8800GTS 640
All other components are probably negligible power draw.

I seem to have stability problems with this chip even with a very mild overclock. Ideally I'd like to get it to 2.8; but I can't seem to push it past something as simple as 210 FSB on stock volts (one would think it would be able to go higher than that).

Are there any tricks that I'm missing? I tried loosening the timings of the RAM as well as drop the HT multiplier.. But alas. At 220 I get errors on Orthos and random crashes in games. At 210 it's stable in Orthos, but I still get random crashes in games.

Any advice would be much appreciated.

Hey man sry i just registered to the site and saw this 6 month old post. If you still need any help with it, i can atleast get you to 2.7 with a stock heatsink and fan setup. I am running the same components, and here is what i am currently running my settings at. If you do end up seeing this and have any questions, let me know, or if you have came up with a better setup let me know

CPU Frequency : 225.0

CPU Voltage : 1.3375v

DDR2 Voltage : 2.1v

MAKE SURE YOU TURN YOUR COOL AND QUIET FEATURE OFF!!!