Shortly after we purchased our 3124KS, we noticed that the door often would not stay closed, even when locked. It was a little disconcerting to leave the trailer with a locked door and then return later to find the door had swing open on its own. I found out that because of misalignment between the halves of the top, the latch's tongue just protruded into the strike plate about 1/16". Any slight movement of the trailer would cause the door to open. Therefore I made an additional strike plate of 1/4" thick aluminum sheet and screwed it over the existing strike plate (using longer screws, of course). Now the door latches in place with slight inward pressure and has not popped open since I made this modification. :
