Yep - although I don't know 100% what the problem was, I think the unit was faulty, and have returned it.
It would power up OK, and you could browse through the menus etc, but when it came to getting an image of a guidestar on the little screen at the back, I had no luck at all - I tried for about 6 hours!
Pity - because it looks like it would be great, and one less thing to have hooked up to the laptop. So I have gone back to a QHY5 - which arrived this afternoon
Adam