Thanks - I've done everything on that list, including tightening the chain (it had some slack in it causing it to droop). The Torsion spring is only about five years old...little by little I've replaced everything (including the garage door) over the years, with the exception of just completely replacing the door opener. So maybe it's just time. I'll probably wait and see what happens when the weather warms up before I decide to replace it. I'll probably continue to use it until it just completely fails.