MIDI Export Not Functional.

This post is regarding the latest nightly rebuild of MuseScore, 2.0 R.5547. MuseScore 1.2 works fine (except for playing grace notes/etc.)

1) Open score
2) File -> Export
3) Select MIDI from the drop down menu.

When the exported MIDI is opened, the file was created IMMENSELY slow.
Is this problem known but being postponed while others are fixed?

Thanks,
Ezra