Incredibly, I fixed the flash on my YN-560 at the suggestion of a helpful commenter. :-O (Kindly stand up and be recognized, sir... :) ). It wasn't as easy as I thought it might be but was not hard either. I will post shots. Caution: I don't know if the fix I did will work for other YN-560 units with zoom issues.
UPDATE: Link to repair here: http://betterfamilyphotos.blogspot.com/2010/08/yongnuo-yn-560-zoom-repair.html