Please help OC P5K vanilla...and you guys rock!

Ok let me first start by saying you guys here kick arse in the baldurs gate series or the old skool D&D boxed set computer games. Ok let's get to my problem. I thought to put it here because it is more MB related *I think*. I have Asus P5K vanilla MB w/latest bios. I am running Vista 64bit ULT. I have 4x1gig sticks of ocz nV sli ready memory in ALL 4 slots. I have a q6600 B3 stepping CPU w/retail heatsink. I am getting my Thermalright Ultra 120 Extreme tomorrow and I am using AS5 thermal paste. I have very good case cooling. I am running my cpu at 320*9 for 2880mhz. I am running my 800mhz rated ddr2 ram at 800mhz. My OS drive and only drive is my 10k WD Raptor 75gig sata. 1 7900GT and 1 Audigy4. Rosewill 750 WATT PS Complete system is updated w/latest updates.

Here is the thing,

Whenever I soft reboot my system Vista starts to load, the little progress bar will stutter then come to a complete STOP. After that it moves a very TINY bit then nothing. Now.....if I shut the system down AND turn the power supply OFF, then ON the power up, it loads fine. If I just shut the system OFF without turning off the power supply, the system fails to load???? It seems that all electricity has to be off when shutdown or the system gets stuck at the OS loading. What is going on here? I have run WD hard drive diagnostic tool in dos and it came up perfectly 0 errors. The cpu has been running fine with 4xprime95 for over 6 hours. The only thing I did not test was the memory which I am going to do tonight. Can one of you guys tell me why I have to cut the electricity everytime I want to boot for the OS to load? Something is not right. Any of you guys have any ideas? Thanks so much I really appreciate it!!!

Could it be the 4 memory banks being filled? Or maybe faulty memory? Please help I am lost.

It almost sounds like a soft-off HD detection problem, are you running the latest BIOS? If not I'd for sure try that.

Btw Q6600 on P5K is not a good combination, the cpu power circut on this board is not strong enough for a quad, don't be surprised if you blow a cap at some point.

I flashed it to the latest bios, removed the cmos and cleared the cmos jumper. Also before when I went to flash it, it said CMOS checksum bad and corrupted my bios. Even though it was the exact bios for my board. So I took that bios file and renamed it P5KBASIC.ROM and put it on a cd. When the system did the bios recovery it found it and everything was peachy. Kinda odd. But I am at a loss. Thanks for the help. You have any other ideas?

Try another Sata port. Or another Sata cable.