New system build

opteron 165 dual core
epox 9npa+ sli
2x512 pc3200 ballistix ram
evga 7800 gt (single)

all at stock speeds

I keep getting error code on cpu test;

"access violation at 0x7c91084b(tried to write to 0x00030ffc)"

I am trying to establish a base line before I overclock and to make sure everything is good at stock