Iomega Zip 100 Plus

I have a client working on a Athlon 650 with an Asus K7V board. It is running Windows 98 Second Edition. I built this computer and know it is a good system. I installed the client’s Iomega Zip 100 Plus drive. The drive is working like it should. Theproblem I am having is that the drive is not correctly reporting the free space of the zip disks. I have reinstalled the drivers, switched to a new zip drive, and have even swithed the mode on the parrallel port. Anyone have any other ideas?