E8400 and Asus P5Q Pro - Can't reach 4ghz - Help!

Hey all, I recently completed my first build after religiously stalking these forums for a few weeks, and it went nicely but now that I've started overclocking I've ran into difficulties. Normally I wouldn't post as I find most answers can be found if you look for them, but I haven't had much luck in finding a solution for this; it seems most people have no problems with these chips.

I've managed to get it stable at 3.6ghz, but it if I up the FSB from 400 to 445 (for 4ghz with a 9x multiplier), I need to set the vcore to about 1.44v (1.41v in windows) to get it to boot into windows, and it fails SmallFFTs instantly. I slowly upped the volts to 1.48v (1.45v windows) and the stability barely improved. The temps seem fine, using a Zalman CNPS 9700 cooler, it reaches just over 60 degrees in RealTemp, but I'm still worried about pushing more volts into it after what I've read on here. I have G-Skill PC8500 1066Mhz ram which I'm underclocking so I know that isn't causing the problem.

The chip is a C0, but from what I've read on here it should easily be capable of 4ghz on much lower volts than what I'm putting into it.

Any advice would be much appreciated!

EDIT: I should also mention I have seen http://forums.overclockers.co.uk/showthread.php?t=17931360 but didn't have any luck.

1.48 on an air cooled wolfdale, wish I had your spare cash!

Try for 3.8 and don't go over 1.35 in windows.

how many sticks of RAM have you got?

Heh, I did think it was a bit high, but I've also read many times on these forums that wolfdales should be fine at 1.5, but generally not to go above 1.4. So 1.35v in windows is the max safe voltage?

2 sticks of 2gb RAM.

Is your memory at its rated voltage?

Yep, it's rated at 2.0-2.1, I had it at 2.0 but just upped it to 2.1 to be sure.

I'm trying it now at 3.8ghz with 1.36v and SmallFFTs just failed after 5 minutes...

Did I get a dodgy chip?

what other voltages you changed?

I had changed most of them but it only seemed to make things worse, so I reset it back to default and have only changed the vcore and ram voltage, rest are on auto.