Has anyone have an overheating issue with this flash? I've shoot wedding and evnts as a hobby. Durning wedding I have to follow the groom and bride to take pictures as they go thru each tables and thanks the guess. After shooting about 20 pictures, my flash overheat. I even bought the battery pack for the flash and it still overheat. Also, i sent my flash in for repair and it came back with flash range turned on, i've searched the manual and online but there's no way to turn that off. Does anyone know how to turn off flash range.