What would cause a Sound Blaster Audigy card to screech when installed on a Biostar M7NCG 400 motherboard?

I have a Biostar M&NCG 400 motherboard and on it I have a Sound Blaster Audigy sound card (PCI). The sound card screeches fiercely during some games. It does not screech when playing system sounds. I thought it was a wire from the fan resting on the sound card and emitting static but that is not it. Any ideas?