Sorry for wasting your time...I just tracked the problem down to smpeg.
I reproduced the problem with some SDL_mixer sample code. I got a segmentation fault inside smpeg when playing that MP3.
Apparently, if you build SDL_mixer with "--enable-music-mp3-mad-gpl", smpeg still gets used at runtime if it's installed, instead of libmad.
Deinstalling smpeg and rebuilding SDL_mixer got rid of the problem.
Now I get to send the same bug report to the smpeg
people. :-)
Steven Boswell