We have a 2010 21wbs - The top of the slide is coming out about a foot on the top going down the road when we turn. You can push on the slide when it is in & the top portion moves very easily and you can push it out about a foot. The slide goes in & out with no problems. Besides putting some kind of bar or wood to keep it from going out what can we do to fix it? We have owned it for 4 years & it just started doing it this last trip.