Door Pin Failure, or Switch Failure?

My GE Advantium microwave acts like the door is open when it is actually closed. The interior light stays on, and the microwave will not work. If I use a screw driver to push on the door switch, the interior light goes off. Is the problem with the switch (that is, the travel distance required to activate the switch has increased)? Or is the problem with the pin on the door which pushes the switch? I've tried pushing the door in and lifting it up (it sags a bit), with no luck.