I've never tried OCing much, I'm not even sure I did it right.
I took a peek in my BIOS and changed the Frequency on the CPU to 333, which I read somewhere someone said it was the "natural overclock" on this CPU. I have a Hyper TX2 Coolermaster Heatsink.
Apparently If I want to get higher Clocks I have to increase the voltage? I'm not sure how to do that or how high I could get it on my ASUS P5GC MX-1333 mobo and be stable.