Have you guys checked the (2) top prep kit inserts to make sure they are tight? They are held in place by (2) screws. I installed mine, leaving them a little loose so the locking pins would "center" in the holes. Then you are to remove the top & tighten them in place. These may be loose.
On another point, can some one point in the direction where the rear locking pin adjustment instructions are? I found it several weeks ago but can't find it now.