have this problem with LSI U320 and Adaptec U320 cards on Tyan S2603 (dual Xeon -603 motherboard). Neither brand Ultra320-R cards will fire up on this motherboard. Both cards are PCI-X 133 and backward compatible. Neither will fire up in the 64 or 32 bit slot. I get an error message that states"Expansion Rom not initialized-PCI Mass Storage Controller Configuration Error at slot 04" or slot 3 depending where I try it. The LSI works fine in a Dell Precision 530 and I'm assuming the Adaptec will too. BTW, I'm running an Adaptec 29160 U160 on this machine without a problem and the board has onboard SCSI which is disabled, but for some reason the U320s won't even startup. Any help appreciated, thanks in advance.