Recently, I've found that exporting the melody with "MIDI file Harmony separate tracks" produces an unusable midi file. It used to work fine. I don't think the change corresponds to either a BiaB or and OS upgrade, so it must be something I did, but I'll be damned if I can think of what.

For purposes of illustration, here's what I'm getting:

This is the basic melody (generated and exported by BiaB): melody

Here it is, with a generic 3-part harmony, exported with "MIDI file Harmony separate tracks" unchecked: harmony 1

Here it is, with a generic 3-part harmony, exported with "MIDI file Harmony separate tracks" checked: harmony 2

I'm using BiaB 2011.5 build 38 in OS X 10.7.4. I've tried deleting preferences and then completely uninstalling and then reinstalling BiaB with no effect.