I've actually exported it about ten times over and over again because there have been countless glitches I didn't notice at first, like not being able to reach portals because of the boundaries, etc, forgetting stuff... What file, do you know, are the .mp3s supposed to go in the first place? I think it's sounds, but I'm not sure. If it's because of that, it may be because they've put the files in multiple places...