Weird multiplier/voltage drop

[Lkd]

Okay so im trying to overclock for Phenom II 550 BE to 3.9 Ghz, but i've stumbled onto a bit of a problem with my voltage not being stable. I can get this cpu to 3.8 at 1.38v no problem. It's just that when i bump the volts up past 1.4 it seems to be unstable and drops down to as low as 1.18 every so often dropping the multiplier and down clocking the core speed to 800 Mhz.

Cool & Quiet is disabled and I'm using a H50 cooler and loads never go above 42 degrees C using IntelBurn.

What do you guys reckon is the problem?

Specs:

AMD Phenom II 550 BE
OCZ 500W
320GB Hard Drive
Sapphire 5770

 

[sirmonkey1985]

it sounds like cool 'n quiet is still on.. in windows set your power profile to high performance.. see if that works.. ya might have to look through the bios to see if there is anything else related to cool 'n quiet.. but those are the exact numbers for cool 'n quiet when its running.. also is this only happening when its idle or when under full load?