BSOD in win2k HEEEEELLLLLPPP!!

I just got my cable modem today and installed UT with the 436 patch and a few level packs. It used to work just fine with my voodoo 5 5500, now I have a GF3, but now after a few minutes of play it tosses up that damned BSOD and says "BAD_POOL_CALL" and reboots. I've tried both 12.41 and 14.70 nvidia drivers and still have the problem.

system:
AMD Athlon Tunderbird 1Ghz
Abit KT7-RAID Mobo
512 MB PC133 SDRAM
Visiontek GeForce3
Hercules GameTheater XP
Win2k SP2 w/ DX8.1a

thanks,
Rides

add on

Just to elaborate on my problem it seems that the BSOD only appears during on-line play I haven't had an instance while playing singleplayer.

Thanks
Rides