Shift+letter to add note to chord not undoable

Ubuntu 14.04, GIT commit: d68ac1e

1) My First Score
2) measure 1, N C Shift+E
3) Undo

Result: the E is not removed. A second undo deletes both notes. I first notices this adding a note to a chord in an existing score I had just loaded: again, the operation was not undoable.