Video drivers Problem atidvag?

I have a nForce4 Motherboard with a AMD 3700+ CPU. 500W ATX 2.03 power supply with 2Gb of duel channel RAM. I get the blue screen of death putting out an atidvag error. I updated my drivers to 8.8 release this august for my card. I am using a Radeon X1550 256mb Graphics card. Can anyone please tell me how to get rid of this problem?

Thanks in advance,

Ray