I don't know the setup of the DVD, but the specification
for ISO image does allow for RISC OS filetypes, which
CDFS on RISC OS understands. I suspect Linux CD handling
doesn't, (although probably easily fixed) and this is where it
needs to be presented. If the files appear with ,xxx extensions,
then SunFish would present the right filetype.
Some more info here:
> I guess another approach would be a filetype guesser
> app to straighten out the mess after copying across.
It would be a guess, and still not be able to tell
lots of things. It's really not worth it. Alternatively,
if things are in a zip archive, copy that over, then uncompress
in RISC OS.