I think I found a bug in SDL_mixer. It seems like SDL_mixer overwrites some
memory when timidity.cfg isn’t found when trying to play a midi file. The
problem is I don’t have a small example. It happens on Win32 in PrBoom
(http://prboom.sourceforge.net) when I’m using the 800x600 resolution and only
in that resolution. It also only happens when using software rendering, the
OpenGL mode isn’t affected. When I turn of music (which doesn’t play anyway) it
works. We also got some other bug reports which we couldn’t reproduce, maybe
they are also caused by this bug.