Ottava not played back after changing span and undoing

Context: commit fd51063 (2015-02-22) self-compiled with Qt Lib 5.3 and Qt Creator 3.3.0 under Linux Mint 17 64-bit.

Steps:

1. Load the attached sample score (created with the commit above) or, presumably, any score containing an Ottava, or just create a score with an Ottava element.
2. Play the score: the Ottava can be heard
3. Edit the Ottava span moving either anchor point (or both).
4. Play the score: the Ottava can be heard and corresponds to the current, edited span.
5. Undo
6. Play the score

Expected result: the Ottava can be heard and corresponds to the original span.

Actual result: no Ottava in the playback in the playback.

Note: If the score is saved and re-loaded after the last step, the Ottava is correctly present in the playback.