ChuckBFL:
If you have access to the code, you could set some Variables in Add Watch and step through to discover what is occurring that prevents the program from finishing. It's very difficult to tell, but unless similar dll files are accessed by the MP3 program and the Excel program, it would be very unlikely that the MP3 player is the cause.
If you discover the cause, please post the solution.
Thanks,
LoNeRaVeR