Duct tape is your friend :doh:is the hinge starting to fail....and by hinge, I mean the thin plastic that bends when you open it. It might be that the bottom seam is starting to separate.
Heavy duty packing tape will fix it.
That seems strange to me. I thought the door and back panel were bolted to the box making it one solid unit....so if the box "rode up" the door would too.....I think I figured it out. The bolts for the seat were loose causing the plastic box to ride up and not catch the latch. Tightening the bolts seems to have fixed it. I usually just hand tighten them so I'll have easy access to the battery. Need to find wings nuts or similar I guess.