Eh? The dir /mnt/iso is owned by root, as are /mnt/cdrom, cdrom2, win_c, etc. The .ISO file itself is probably owned by root since it's on a DVD.
It wouldn't have anything to do with the /dev/loopx 'files', would it?
Would I have to create a new group 'isomount', chown the /dev/loopx files to isomount, and add the normal users to isomount?