is there an issue with this board and SLI gtx295s?

both my cards work great alone.... and each card works fine in either slot... but 2 in SLI causes discoloration, tearing, pixilation, etc. anything physx locks the machine up.

i've reinstalled OS many times, used different drivers, different power supplies, different ram. no fix.

same hardware on my UD5 works flawlessly.

whats going on here?