Crash on fast auto-annotations update in expert discovery

1. Launch Expert Discover plugin from the tools menu.
2. Click "Open Expert Discovery document" button on the toolbar.
3. Chose the attached file
4. Right mouse button click on the item "Positive". Click "Show sequences" from the contex menu
5. Expand the "Markup" and the "LETTERS" items.
6. Try change the items (A,C,G,T) fast (using arrows on the keyboard)

It crashes after one or several rounds up and down.