Hi Tony,
What you have is classic symptoms of field rotation error. You need to get the scope precisely polar aligned to fix this. This is a common problem, and one I have to deal with everytime I setup. What is happenning is that the arc that the scope is moving is not the same arc as the sky is moving. So even though your star is staying put the sky is rotating every so slighly around it.
a good explanation of polar alignment and how to do it accurately is here
http://members.aol.com/ccdastro/drift-align.htm
Once you get that sorted you'll be away. Hope this helps.
Cheers