And it was again a bug which looked like nothing and was after all critical, this time a race condition on the sdl_sound sample when using this game this way. For some reason it didn't happen with the bin files, maybe because operations on these files are quicker. Anyway I had to move all the operations on this sample outside the callback, which is the opposite of what we did with sdl1... ! Normally it's safer this way, and your crash is finally gone.
I started by updating sdl_sound, but it was not the cause, I'll keep the sdl_sound update anyway (for flac, ogg and mp3).
Hoping that it didn't break anything else, I tested an sound association in kof97 and everything seems fine (uses the same method, an sdl_sound sample).