Over the last few days I have noticed that my MAG 322 Remote Control is misbehaving. The OK button and the left/right, up/down arrow keys do not work; channel + works, but channel - does not. MODE works, but SETUP does not. Tried powering down the box, and removing batteries from remote, then restarting, but still the same. Is the remote definitely faulty, or have I inadvertently pressed a wrong button to make it misbehave?