if it randomly clicks the contacts on the multi funtion switch are dirty. There is a how to over on gagt.com telling how to clean them, check it out, it happened on my buddy's gagt, cleaned it up and no more clicking.
http://www.grandamgt.com/forum/showthread.php?t=50126
There ya go, i found it for you. Its not hard to do, just make sure to follow the directions.