As I explained on IRC yesterday, this happens because the MOD pattern data is within the Amiga limits, so OpenMPT plays it like ProTracker would. However, I have applied some other heuristics in r10989 which make the file play correctly (it has zero-length loops for unlooped samples, so it wasn't saved in ProTracker and thus ProTracker quirks should not apply).

In the future, to be more easily able to control playback of such troublesome files without adding more heuristics we need to implement 0000779.