BrntToast, right on the money. Sounds like my problem, although does not list my model as you point out and I am definitely not in a high humidity environment (Michigan).
I have taken the baffle/motor out enough to speculate (I'm just an engineer - civil though) that the part is probably some sort of gasketing or isolator from the damper/air flow to the controls.
How should I contact the Whirlpool techies to see if I can use it in my application?