Hi John,
I had that M-Audio Transit some time ago. If it is XP then problem with driver can be easily fixed, that is about system's permission for unsigned drivers. M-Audio documentation is not useful in this, thats right.
Later I found one other solution how to get spdif for laptop - docking station with coax spdif connector. From ebay it was much cheaper then M-Audio Transit. Maybe you can think about it too.