VERY strange prescott problem

[creepah]

hi good ppl :)
I have the "PT8 Neo-V MS-7043" mobo, and I just bought a Intel Pentium4 Prescott 3ghz (fsb 800mhz HT) for that motherboard (wich is supported)
I had a Pentium4 Northwood before @ 2.53ghz/533mhz fsb, wich worked FINE.. no problem at all
when I tryed the new one i started getting problems with my OS
internet explorer crashed sometimes
I got CRC errors in rar archives (wich unpacked fine with the old CPU)
I got errors in benchmark apps, like prime95 and 3DMark03
so I thought it might be the os, so I reinstalled the OS, didnt help!
I updated all chipsetdrivers, flashed bios, turned HT off in bios, tryed other PSU (running @350W 5V@35A | 12V@17A | 3.3V@20A, right now) to low?
I tryed the CPU in another computer, worked fine.. only did the torture test with prime95 and unpacked a rar archive, but it worked fine.
Ive got a tip that it could be the DDR RAM, I have PC2700 ram default, so I tryed PC3200 memories.. didnt help :((
feels like Ive tryed it all, with no success
one funny thing.. when I reset the bios (with the jumper) and boot up, the cpu workes fine for a while.. then after rebooting its back to normal "crappy" cpu.. dont know what to make of that :P
if any1 could help me just a bit Im more then greatful!
greetz!

[Sucka]

Did you flash to the latest BIOS? The board might support Prescott, but you might be running an old BIOS version.

[creepah]

sure did, the mobo had the latest when I got it (1.90), but I flashed it anyway to make sure.. I even tryed an older biosversion 1.80, didnt help much :(

[creepah]

haha, I found the problem! I increesed the vcore with 0.07v and it did the job! :D the vcore was to low default.. thats kinda bad thought.. but damn Im happy :D