Pressing Delete and Backspace doesn't emit the triggered() signal for Delete and Backspace keyboard shortcuts. Other shortcut keys, such as Ctrl+X, work.
The Delete and Backspace shortcuts work in Qt5.0.2, but not anymore in Qt5.1.0.
The attached example can be used to test this. Pressing Ctrl-X changes the label but delete or backspace do not. Also, for some reason, the Delete menu item doesn't display the shortcut symbol, but that is not so important.