I have a 4 y/o AE insert. I've continually (since new) had pellets getting wedged behind the back edge of the top and the frame around the unit. Also the rubber gasket covering the top edge of the sheet metal has pulled off. The tech seemed to think it was because I was jamming the bag into the hopper while loading, which is not what I do.
I pulled the 4 bolts holding the top, lifted the top, and pushed the gasket back into place, but it appears the sheet metal is bowed forward, and not sitting under the lid. Right now I've got a 3" wide roll of electrical tape to run from the back wall, over the lip and the gasket, and into the hopper. Any better suggestions would be welcome.
Note: if you lift the lid keep in mind the top hinge pin on the door will come loose and the door will drop. Fortunately the ding in the floor is not too noticeable