I've been using a Bluetooth mouse and Logitech K360 Keyboard with my macmini running 10.9.5 without incident for quite a while. Yesterday the keyboard went nuts. At first the "c" key stopped working, then it just got crazier, with keystrokes trigging random actions like opening search windows, activating characters not associated, just generally nuts. The mouse seems to be behaving normally. Bluetooth is obviously working, though neither the Keyboard or Logitech control panel can see the keyboard. Put in new batteries, restarted computer, switched keyboard on/off, nada. So far I have resisted massaging it with a very large hammer. I had a sticky key at one point due to a drop of wayward Tamari sauce, which I freed with a little isopropyl alcohol. This produced no adverse reaction at the time. I thought a little alcohol would be benign, and so it seemed. I can't think of anything else that could be a cause. A regular USB keyboard works fine. Is the Logitech toast?