if you like slamming your doors like so many people do, or even if you don't, just the factor of time means that the metal has definitely bent outward at the top of the door. Or in other words the window frame has bent out slightly. My parents own a glass shop and work on auto glass. They see this all the time and the only fix is to physically bend the frame back in alittle. Give it a good grab and see what you can do haha I would still first check the pin and all that to make sure its not moved or worn, but i'd put my money on the frame, ive seen it happen so many times