When burning a disk, apparently the files are renumbered. I haven't verified by doing it myself, but model who I've burned disks for give me numbers from disks that I've burned for them that don't match the number of the photos I took of them.
I looked for some kind of checkbox for use same number or renumber during burn and don't find such a thing. Confusing.
I'll have to actually burn one and look at it myself, but it's happened several times now. I'm running out the door while burning another disk just now and had to ask so I get this resolved.