Game Flickering

Babidi - Heavens Tear

HI. some 3-4 weeks ago, while playin PW my screen started to flicker every 30 seconds or so. this did not use to happen before.

my pc is brand new:

core 2 quad q9550 2.83GHZ
4 GB RAM DDR
geforce GTX 285
500gb HDD sata II
LG M2294A HD screen

this flickering does NOT happen while playing other games like NFS undercover and Crysis (GPU and CPU intensive).

my PW settings are all maxed out (highest Detail) resolution at 1680x1050, tried at low setting but it still flickers, tried with v-sync on but same problem.

screen refresh rate is at 60Hz ( cannot set it higher, only option i hav is 59hz or 60)

GPU temp while playing PW is 67 degrees celsius, so thats pretty normal.

power supply is 400W, now this might be the problem but then again flickering does not occur when i play nfs undercover which is more demanding than PW. my pc however restarts after a few minutes of playing crysis becoz it requires a bigger Power supply.

please remember that this flickering did not use to happen be4 and there are no mobiles or anything like that interefering with my screen.

any input is appreciated, thx