Autosave works only the first time

MuseScore 0.9.6.1

1. Open MuseScore and be sure that autosave is on every 2 minutes
2. Create a score
3. Add a couple of notes and save the score
4. Add more notes
5. Wait 2 minutes an check the sessions directory. A file will appear.
6. Add more notes
7. Wait for 2 minutes and check the session directory

Actual behavior : The file in the session directory is not written again.
Expected behavior : The file in the session directory should be updated with the last notes added.