Cannot add more than one button in a Workflow Task

1. Create a workflow
2. Drag and drop any task
3. Edit the task
4. Click the Resolution Actions tab
5. add abc in the id and label fields
6. click save
7. Open the task again
8. Click save and an error message appears "A button with name abc already exists"
9. Click cancel
10. Click Add task button
11. Observe no new button is displayed but rather the existing abc button slides down
12. Click multiple times and observe the abc button line being slid down
13. Click cancel
14. Open the task again
15. Observe the changes are still in place and were not cancelled at all.
16. Select the abc button
17. Delete it
18. Click save
19. Now open again the task
20. Clic Add task button
21. Observe the abc button is coming back!

Expected behavior: adding a button should be a simple matter and work out of the box.
Note: It seems there are multiple problems here but Studio behavior should be consistent and clicking cancel should make the Studio forget it.

Note 2: adding buttons in the other tabs works fine.