>>>> produces no sound output.

Ryan, I think it has something to do with some interesting code in virtch2.c
;-)

#if defined(macintosh) || defined(__APPLE__)
#define NO_64BIT_MIXER
#endif
[... snip ...]

#ifdef NO_64BIT_MIXER
                                /* Uh oh, the 64-bit mixers don't compile...
*/;
#else

The latter essentially translates to "produce no output if the song is long
enough", where 'long enough' is a few milliseconds at 22.5KHz.
We should see how later versions of MikMod handled 64bit ints on Apple
compilers.

-Alex.