Hmm.... Double check your termination and cabling, perhaps?
Termination should be set on the card if no external devices are plugged into it. Termination should also be set on the hard drive, since it would be the last device on the chain. Bad cable will also cause similiar problems.
Of course, a fried SCSI interface chip could also be causing your woes. That might be easy to fix, though, if it's socketed.
I wouldn't chalk up the card as a loss quite yet. And even if you did, keep the RAM, as GVP SIMMS are still hard to find. ;-)