I am using this fibre card for both windows NT 4 and Windows 2000 ADV svr 
(connected to a SAN). There are different drivers for Win2000 (but win2000 
picks up the LP8000 - you need to change this - use update driver and tell it 
to use Windows update). You also require a different client to backup directly 
to tape (LAN FREE) (see SAN storage agent guide), however if this path is not 
found it will use the LAN path to get to the diskpools.

Not sure about the RS/6000, but if it is attached to the SAN with your library 
then why not?!

Server - Windows2000 TSM v4.2.1.6

Joe