The filesystem is the problem, presumably an old version of CrossDOS which can handle only DOS 8+3 filenames. Either get a newer version (commercial) or use
Fat95 instead (free, on Aminet) to get the full Windows filenames.
If you want to stick with the old version of CrossDOS there are a couple of progs that will copy the files off the disk and restore the full filename:
dos2amigafilename95Easy peasy.