Umax e3420 problem (hardware?)

I just purchased an inexpensive flatbed scanner, as most (95%) of my
scanning is 35mm film scans for which I have a dedicated film scanner.
Unfortunately, the Umax AstraNET e3420  USB scanner is not working
correctly. The first scan I do is fine, but subsequent scans either come
out blank (white) or more often totally red, as if only the red exposure
is taking place. An e-mail to Umax suggested uninstalling and
re-installing the software, but that didn't help. My feeling is that
it's a hardware problem not software.

I'm using Windows 98SE, Pentium III 500 with 384mb of ram. I almost
always use the import (aquire?) command from within PhotoShop 5.02. Any
ideas from anybody?

David Azose
draz @seanet.com