I also posted this question on the Yahoo group for PDN, and recieved some answers. In addition, Epson emailed me back and said they do not plan on updating the driver with features (extended print head pass times) that could fix this problem.
While I can remove the pizza wheels in my R800 (I've done it before), I fear it will cause future problems (my last R800 started scratching prints some time after). Also, the paper is not held down, and the last 1-2 inches are smeared because of this. Mark offered the suggestion that you could tape another piece of paper to it so it will keep it flat through the printing process.
Right now I'm fairly angry with Epson, due to their lack of tech support, and also how their software manages inks.
Aside from that, I might take a look at the new HP pigment printer. Someone else posted success with an Epson R220 I think. Epson came out with a few new printers, R260 with 1.5 pic, but I don't think anyone has tested it for digital negatives.
I'll have to give this some more thought, and see if I should try modifying (removing pizza wheels) or look for a new printer.
Regards,
Martin