Little problem with my Nikon D3100? - 1

The little flap that covers the USB port doesn't close anymore. If you click the link above you can see it. If I try to jam it in there it just pops back out. I heard that rubber expands in heat so I was wondering if that was the problem. Has anyone had this problem or does anyone know how to fix it? I thought about cutting it a little but I want to sell this camera when I upgrade.

I would take the camera to a local camera repair shop and have someone there take a look at the part in question, get an estimate on a repair or a parts replacement or quiz the camera company and ship the camera back if it is still in warranty for a repair there.

A good thing to do keeping the camera in original condition, especially for selling it later.