you must have them the wrong way round, all my mp4s play and have the structure:
Atom ftyp @ 0 of size: 24, ends @ 24
Atom moov @ 24 of size: 93274, ends @ 93298
Atom mdat @ 93298 of size: 24569738, ends @ 24663036
Atom free @ 24663036 of size: 59, ends @ 24663095