Just as the title says. Have a 1-1/2 year old Ultrex. Last week I turned on the Nav switch, cranked the motor on high and cruised to my next spot. Slowed down my speed and the Nav switch would not shut off. Had to use the end of my needlenose pliers and press real hard to shut it off. Feels like some sort of spring isn't working right. Anyone got any ideas what the issue might be?