Have you EVER used "mp3tofid" ?

Apparently version 3.00 (and higher) of mp3tofid uses the new format.

It is important to determine how this happened, because whatever did it was buggy -- it created duplicates of the root playlist and several other files -- your music directory structure is basically corrupted at this point, with some things in the new format, and others duplicated in the old format. No guarantees as to which copies of the playlists will be used when sync'ing the player with Emplode ...

-ml