5600xt and NV4_DISP.DLL BSOD

Hi all, while playing games such as final fantasy xi and everquest2 my machine will instantly boot me to desktop without error message, and at other times i will get an instant BSOD and reboot containing the error message with the NV4_DISP.DLL file. im pretty sure the 2 are connected and with online rpgs like that i dissapear from groups at key moments and am losing friends lol. ive looked everywhere for information and also been talking to both the ffxi and eq2 tech support and neither have any answers. ive reverted to older drivers and still no luck.so if any1 can help id be very grateful^^

amd ahthlon 3200+ barton (Stock)
1024MB DDR 3200
FX5600 256MB XT (Stock)
GA-7N400 MOBO NFORCE2
120GB SEAGATE SATA
650W PSU