Try resetting the board to factory defaults. On my Asus board there are a pair of jumpers to short out to do this, check your motherboard manual to see if there's a similar procedure.
At the least you need to change the voltage to OCZ's specification, at 800mhz they all generally require less voltage. Some bios have EPP mode where you can select that as well as EPP voltage as well. Enhanced Profile P? sorry alheimers
Try resetting the board to factory defaults. On my Asus board there are a pair of jumpers to short out to do this, check your motherboard manual to see if there's a similar procedure.