Thanks for the replies guys.

A couple of comments:

The card was on its own, no other NuBus cards to contend with it.

All NuBus slots work fine (with another card, not SCSI though)

I'm not trying to boot off the card, just see the drive attached to it. Still booting from the internal device.

I read the entire manual(s), but they're really terse. No good trouble-shooting section.

Lastly, I'm not sure about SCSI Manager ROM versions. More specifically?

A related link for those who might stumble upon this thread in the future:

http://xlr8yourmac.com/SCSI/atto_oem_flashrom_tip.html