Hi James,
Check to make sure you have the cable going to the "in" scsi port for the scanner, not the OUT port It shouldnt matter but it can.
The next thing is termination - For a chain of SCSI devices to work properly it needs to be terminated at each end. Since you have only the card and the scanner, and the card automatically terminates one end, check to verify the scanner is properly terminated You should have a switch near the port and/or the dial. If you dont have the switch you may have to buy a termination block for the other end.
Is the scanner new or used? The same question for the SCSI cable, is it new? If its used look at the ends and verify all the pins/contact slides are intact. If you have a spare cable try that, if for no other reason than to remove the cable from equasion.
Since scanners do not have embedded driver support, you will be required to install a scanner driver. Once this is installed it will be listed in Device Manager under Scanner. Have you installed the scanner driver?
Which ASPI agent do you have installed? The one for the card or the one for the scanner?
Go here for M$ help:
http://support.microsoft.com/default...b;en-us;133285
Please let me know if any of this helps.