I had some damage caused by leaving my pooch in the trailer while moving campsites and left the rear bunk open!  There were a bunch of little screws (about 12 of them) that I removed, then took the bunk end out of the little slot.  Had the canvas repaired at a boat place, then re-installed.  You may want to simply add another tiny screw or two which should go through the aluminum slot and into the canvas backing.  Like 1/4 inch screws I had to buy a special #1 sized roberson bit but worked like a charm.  Good luck