I've tested it now (something to do in the easter :D).
When I tried installing from the ISO, it failed to detect it, so I put in a lowly 3COM which it found immediately.
I just shut the firewall down yesterday, and tried putting in the IBM card.
When it booted up again, it detected it perfectly, asking me to assign WAN and OPT1.
A bit of a difference there, between the ISO installation and bootup for some reason.
Well it works, so I'm a happy camper, very nifty tiny firewall, with three NIC's now, all made from 'scrap metal' ;D