Athlon XP 2800+ Barton HELP!

Hi,

I'm trying to overclock my old Barton 2800+ but it won't run even at it's normal speed :/

It's locked to 12,5x and I tried to run it at 12,5x166/33=2075mhz. I ran Prime95 for over 24 hours but 3DMark06 makes the computer boot at the beginning of the first test. The new game called SPORE also works for a second until the comp boots. The funny thing is that if I underclock it to 12,5x133/33=1667mhz everything works fine! 3DMark06 runs fine all the way (okay with 1-4 FPS :D) and SPORE works without glitches. I've also tried other FSB values and Vcore from 1.650 to 1.850. I can get 2,25ghz to work with Prime95 stressing but 3DMark06 or games still won't work. :O

PLEASE help me get this problem solved, any assistance will be much appreciated! =)

My system:
Asus A7V8X-X with VIA KT400
Kingston DDR333 non-ecc, 1 bank 512mb + 1 bank 1024mb = 1,5gb
Antec TruePower 380W PSU
Club3D Radeon HD 2400

That processor is not OC friendly. I will sell it on eBay and get a 2600 AMD XP-M or a 2500 AMD XP-M.

They are laptop processors so they run cooler with less voltages and better yet they are factory UNLOCKED.

I still have my DFI LP NF2 pumping a 2600AMD-XP-M at 10x270Mhz (2700Mhz) with 1.775vcore.

You mean the AMD XP-M, make sure they are the ones with default vcore of 1.45v (if I remember correctly).