The player uses only the first 32K of the file to decide if it is an MP3 or not. If it doesn't find two consecutive valid MP3 frames in that part of the file it decides that the file isn't an MP3 file and gives up. The file may be being identified as invalid because it has rubbish (possibly a large ID3v2 tag) on the beginning of the file or it uses space between frames to store other information.

I've personally got a tool in development that removes junk from MP3 files. Some of the stuff it uses may make its way into emplode in the future. At the moment it is Linux command line program - I intend to make it compilable for Windows and to add a simple GUI for Linux and Windows in the future. Unfortunately I don't get much time to do my own development these days so it isn't really in a releasable state :(

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Mike Crowe
I may not be speaking on behalf of empeg above :-)