Maxtor 3100 'unknown device' when connected to Adaptec USB2Connect (AUA 5100)

Anyone have experience with why Windows XP Home will NOT recognize (ie., "unknown device") when Maxtor 3100 (USB) is connected through Adaptec AUA 5100.

Windows XP Home recognizes drive properly if plugged directly into mother board USB connector!

John

I have that same Adaptec card, although it's installed in my older Windows 98se machine. Is the card driver installed? Any yellow marks next to it in the Device Manager?