After several days of working on this problem, it seems obvious that the sane package will not support the transparency unit on the Epson 2480. After working for two days with the latest sane-backends package (1.0.16) and having more problems than with the older version, I have dropped back down to 1.0.15. This has not solved my problems with the color banding on slide scans, but at least it works again for flatbed sources. Now I just have to decide whether to buy a machine to use as a dedicated scan server (Windows... Yecchhh) or buy a film scanner that is known to work on Linux (lots of money).
Good luck to anyone else trying to get this combination to work. ken
