Cold weather can make the boards act up ! Had a similar problem with both my Powerstar 8" and Ultima 11" ! Returned them to Celestron and they were fixed but that was back in 1993 and 1996 in that order !Both scopes were still under warranty . Odd that Celestron doesn't offer info on the matter since they evidently fixed mine ! I have used both scopes in really cold weather since (-20 F) and have not had any problems . In fact my 11" is mounted in an observatory so is exposed constantly !A man named Victor who headed the sales and service department at Celestron helped me out quite a bit when I had the problems . Maybe he could help you if he is still there!Don't recall his last name but it was something like Anesito !

Regards
Tony B