Strangely enough I've had one of these here for a while now (abought 6 weeks I think). After talking honestly to customer about parts prices he bought another car as a runaround (nice guy!).
Any way, I cleaned the body on this one but it would not re-learn, after talking to a dealer tech he mentioned that there is a coupling between the motor (it's actually just a rotary solenoid)and the butterfly that can break. I am going to have another look today to see if this is the case. Will report back later.