I'll have to take another look at mine but I believe you are missing a lip turned up on the back of the aft slider hatch. (the one without the handle) It tucks up underneath the lip down on the forward hatch so when you pull the rear hatch foward it catches the front hatch and they both pull togeher the rest of the way....not sure if thats clear but take a look for some pics on the site that show it....