Improper behavior when delete after alter chordname.

STR:
1. add some random notes. (3 bars of "B" quarter notes).
2. select a note, ctrl-k for chordname and enter chordname (eg: "E")
3. select another note farther in time via space bar and again enter chordname (E).
4, using space bar select another note and add different chordname (Db).
5. using mouse, select 1st chordname. When box appears, use mouse to move cursor behind E and add 7.
6. double click on first chordname, move cursor to behind "E" with mouse and add "7". Double click on 2nd "E" and follow same procedure.
7. Using mouse, select 3rd chordname (Db) and press delete.

Expected result: chordname disappears.

Actual result: chordname does not disappear until reload.