Another forum member put me on the right track, I had exactly the same problem (thanks again slice of heaven!).
Try grabbing a torch and shining it into the side of the Cheshire (into the big hole) and try it again. I used my red astro-torch and it works great (even at night!).
Have to wait about 2 weeks for them though as Lee Andrews is on holidays in China at the moment. (holidays my foot! Bet he is checking out the Synta buy-out of Celestron and looking for deals. He could come back with some interesting news from GS too)