Overclocking Q9550 with Zalman & Asus mobo

[Mudokon]

Specs are:

Q9550 C1 Core2Quad
Corsairs XMS2 800 mhz (pc2-6400) ddr2 dual channel
Asus P5k-Deluxe Wifi socket 775
evga nvidia 580gtx
750w corsairs p.s.

I overclocked via someone elses guide here on the forums from awhile ago and achieve 3.8ghz on air but the power test had one of the cores fail and then i had battlefield 3 crashing, so i reset it back to normal, but I'm still get instability hitching.

Not sure if I messed something up? Or need to reset something.

Thanks! (i know its an older machine, but I thought you guys could help) :)

[celery952]

3.8 is about the wall for me on mine acted funky recently and I dropped it to 3.7 I have a dfi mobo so its like greek to me lol