Slack in the actuator tube or the mounting hardware at the dish-attachment points will cause inaccurate stops as the dish travels, mine does it sometimes. And yes I discovered some ABC channels on 99w the other day, that I didnt know about. Don't know how long they've been there, I'm sure there's lots of things on c-band I still haven't found yet, too. Those Virgin Island feeds have been there quite a while though.