If your MP3 file starts up with a bunch of bitmap garbage that's something other than MP3 audio frames, how is the importer going to know that it's really an MP3 file?

Pardon me for saying, but that doesn't quite make sense. I haven't read the spec, but it would be silly if it said "look for this signature to find the music data". You'd have to have a hecka long signature to keep from accidently grabbing the wrong data.

Anyway, you reminded me of another problem we used to run into with tagged image files like TIFF. I bet it has more to do with the fact that the start of music data was at a fixed offset in early revisions of the specification. With the advent of "bitmap garbage" ;-) and tons of other tag data, someone got clever and put oversized header data (or perhaps just oversized tag data) at the end of the file, making some players break.

Again, I seriously doubt the code is "scanning" the file for valid data, but rather it doesn't know where to look for a relocated header or tag.

Sorry to be a pain - I've mostly just started deleting the art data. The music is more important!