the clicker has been flatened, had the same thing happen to mine after sitting on it for a long time.
link
go here and see where he peels the orange sticky pad back? there is a litle mettle "dish" in there that is supposed to be dome shaped. mine was flattened out which meant no clicking. i took my tweezers and bent it back up in the middle, stuck it back on and there you go! hope this helps