Editing case properties malfunctions.

Note: I haven't checked if this is fixed in the latest version. Will do that asap but I'm making an issue so that I don't forget.

1. Create an unassigend case.
2. Add a comment while assigning it to user1.
3. The comment will now say Anonymous > user1;
4. Click edit.
5. Assign it to user2 in stead of user1 and submit.
6. The comment will now say user1 > user2.

I think that after editing it should say Anonymous > user2. Because there is no longer a trace of it being assigned to user1.