“incorrect Function” error

When I try to access my USB ZIP drive (or even my floppy drive for that matter) in Win XP Pro, I get an error “:\is not accessable. Incorrect function.” I’ve deleted and re-added in the device manager, and the system recognizes these drives, but still gives the same error when I try to access them. I’ve gone to the knowledge base to get an answer, but get nothing. I have no SCSI drives on my system. Any ideas?