[Trunk] Time signature change broken

1. Create 4/4 score.
2. Drag 2/4, 3/4, 5/4, 6/4, 3/8, 6/8, 9/8 or 12/8 time signature onto first bar.

Result: Time signature is 4/4 - visually and in playback.

2. Drag 2/2, 4/4 common time or 2/2 alla breve time signatures onto first bar.

Result: It appears, but playback is 4/4. Undo doesn't work either.

Using MuseScore 2.0 Nightly Build (5223) - Mac 10.6.8.