Dave, thanks for your reply. What has happened is that the two small blocks of wood that attach to the screws have become unglued from the cover, so I guess I have to reglue them. Any suggestion about the glue?
Below there is a small plastic tab attached to the cover that fits into a tab on the AC control unit. That should help to secure the unit.
One more thing. On the top part of the back of the cover there are two spots (roughly above the two lower ones) that appear to have supported also two glued wooden pieces. Do you know anything about that?


JL