Part bug

There's a bug I discovered that only seems to be reproducible sometimes (don't know why). I tried on other machines (Mac 10.6.7 and Windows XP SP3), but I didn't get a crash (maybe it does though). Slightly different steps each time, but I noted the ones below. I wonder if anyone could help.

1. Open score.
2. Create part.
3. Open Part box.
4. Delete part.
5. Create another part.
6. Close Part box.
7. Close score.
8. Don't save.

Result = Crash.

Using MuseScore 2.0 Nightly Build (4300) - Mac 10.4.11.