I had a night of really good guiding last night which went pear shaped in the last 20 minutes of my run on NGC281 (pacman). Really puzzled about it, as at first I though it was a cable snagged but no, they were all ok. So I have come to the conclusion it had something to do with the position of the 'scope in the last 20 minutes of an hour long run, possibly a gremlin as I've never seen this fault before.