I'm still having trouble with my 40F. Sometimes it works great and then out of the blue it starts acting up. When I move the controller to go up it keeps going down, when I move it to down it still goes down and other times it does just the opposite and won't let me down. The forward and reverse acts up the same way or doesn't move at all. Then all of a sudden it will all work fine for several days. Warmer temperatures seem to help. Any body have any thoughts?