I changed to the 150 newt as I was getting elongated stars through the 80mm refractor. Think I've found the problem, loose mirror on the (El Cheapo) diagonal being shaken by the drive motor. Didn't think there would be enough vibration to cause that, but there you go. A dab of liquid nails between the mirror and the back cover should fix it.
Adding a good one to the christmas list.
Becoming a bit more patient with the DSI, its not so bad really
