Frigidaire PLES389ECC Door won't stay closed

Question

I have the Frigidaire PLES389ECC slide-In glass top oven. It is about 1.5 years old. Upon heating the oven the door begins to open slightly. The light in the oven will eventually come on as the switch is near the point of full extension and contact is made and the light comes on. It is almost like the gasket expands as you can look at the door from the side and see the slight angle that is formed between the oven frame and the door's edge. The best I can guess is the gasket is expanding. Should the door gasket expand to the point that it causes this?? I just don't know what to do!Thanks,Bob