I have the new 798c HD SI mounted at the front of my boat with the trolling motor transducer. Everytime I pull up the trolling motor without shutting off my unit, the unit freezes and I have to unplug it from the quick disconect mount and power it back on. Is there something wrong with my unit? or should I just be getting in the habbit of turing the unit off before pulling the trolling motor out of the water?