I just encountered this bug too. I use the key shortcut for a menu item with a "D" shortcut. Then I tap the arrow keys on the keyboard. After that, the "D" key no longer works. Selecting a text view elsewhere in the app, then clicking back into my app view makes the problem go away. I found no work-around relatesd to switching firtst repsonders, selecying a text field programmatically, etc.