Ok...I need some help

I have been trying to OC my system for about a week now trying every single BIOS config I can think of, and nothing is stable in Prime95. @3.75 Ghz W/2500Mhz FSB
I can play COD Black Ops for hours without a fail but it barely makes it 5 minutes in prime?? I'm not a complete OC'ing noob, I understand the concept and the things that need to be done but there are just soo many adjustments (especially memory, which is where i think my problem is because I can run small FFT's in Prime all day with out error)

Hardware

MotherBoard- ASUS M4A-785-M
CPU- AMD Athlon II X 2 250 stock rated @3.0 Ghz (Currently @ 3.65 Ghz\ 1.46 VCORE\ 32C Idle 45C Load
CPU Cooler- CM Hyper 212+ (single Fan)
RAM-OCZ GOLD DDR-2 800/PC 6400/5-5-5-15-20-2T 1.8V( Currently at 816.8Mhz\6-6-6-18-24-2T\@2.1V
GPU- Sapphire Radeon 4830 512MB (Currenty @ 710/1050)+
HDD-2xWD AAKS 500 (RAID-0)
PSU-Coolermaster 600W (yeah it's cheap, I'm aware : ) )


Current BIOS Config

CPU OVERCLOCK: MANUAL
CPU/HT REF CLOCK: 245
CPU FREQ MULTIPLIER: 15 X (Locked)
CPU-NB FREQ MULTIPLIER: 10 X
CPU OVER VOLT: 1.50V (In BIOS, reading 1.46 to 1.49 in CPU-Z and PC Probe)
VDD-NB OVER VOLT: 1.35V
LOAD LINE CONFIG: AUTO
HT LINK SPEED: 1600Mhz
HT LINK SIZE: AUTO
HT LINK OVER VOLT: 1.21
MEMCLOCK MODE: MANUAL
MEMCLOCK: 333 (already reduced from 400)
DRAM TIMING: DCT-0
TCL-6
TRCD-6
TRD-6
TRTP-3-5
TRAS-18
TRC-24
TWR-AUTO
TRRD-5
TRWTTO-AUTO
TWRRD-AUTO
TWTR-AUTO
TWRWR-AUTO
TRDRD-AUTO
TRFC0-AUTO
TRFC1-AUTO
TRFC2-AUTO
TRFC3-AUTO

MEMORY OVER VOLT 2.1V
CHIPSET OVER VOLT 1.31V

Current clock 3.65Ghz
Current FSB 2450Mhz
Current HT LINK 1960Mhz

From everything I have read this looks about where I should be yet it is still not stable.
Any input greatly appreciated, Thanks in advance.