Just hang onto them until the next firmware revision. 8x -R is still very new (this is the first time FUJIFILM03 has been out on the market, AFAIK), and many drives are still having media support issues with various 8x -R media.
(Personally, I would’ve tried to get some +R media instead of -R media… in a LiteOn, good 4x +R can trounce good 8x -R any day in terms of both compatibility and quality).
Edit: (in response to your edit…) Yes, you can change the ProdiscS04 code to FUJIFILM03 if you really want. I dunno how well this would work out. If you’re right about the two media types being the same, then it’ll work well. Otherwise, it’ll probably make you a lovely coaster.