Guys, just purchased this toy hauler and the side-door opens just fine when standing on it's own. when I hook it up to my truck, the door has issues. what have you done to correct this? yes, it 13 years old, but there must be something that could be adjusted? all trailers flex in certain conditions, and this one isn't so bad unless I need to get in the trailer while still hooked up to the truck. Can the door be adjusted for this???