Thanks for letting me know you experiences... I am going to add a rivet or two in the area around the door....
By-the-way, I pulled this trailer for 11 years (approx 22000 miles) with a chevy 2500, without a weight distribution hitch and never lost a rivet. The first pull with my new sierra 1500
with a Husky Centerline (with the lightest bars they make: 500lb to 800lb) and I loose 2 exterior rivets. Its easy to jump to the conclusion that the weight distro hitch caused it, but the pull was from Alabama to South Dakota over some rough roads in between.