Deleting note from voice 2 chord disables automatic stem direction by voice

Ubuntu 14.04, GIT commit: d68ac1e

1) My First Score
2) measure 1 note entry
3) voice 1: 6 C C
4) voice 2: 6 A A Shift+E (also in measure 1)
4) Esc to exit note entry
5) click the "E"
6) Delete

Result: the sterms flip - the voice 1 notes get stems down, voice 2 get stems up. The effect is as if there was only voice - notes above the middle line get stems down, notes below gets stems up. I guess maybe "hasVoices" is getting cleared.