ZIP 250 USB probs

[FiberOptik]

I can't get win2k to properly communicate with my zip250. Win2k will correctly recognize the drive when I plug it into my computer. However, when I try and access the drive I get the following error "the request could not be performed because of an I/O device error." The strange part is that the drive will work sometimes when win2k is in safe mode. What am I missing here?