Item that has been added back to DB vanishes

[PiispaH]

1. Open fresh DB
2. add new scenario A
3. Commit changes
4. Remove the scenario A
5. Type A again into the "add new scenario" -field to add it back
6. Commit changes
7. Reopen db editor -> scenario A is gone

Same thing happens with alternatives and entity classes. Pressing the refresh button after step 6 doesn't remove the added item.