Yes - the problem didn't show up until I added the shipping rules.... if I eliminate them then all is well. I had posted screenshot of an example of what I did when I set it up - In the ecart object panel I set up the rules under the 'shipping' tab - was that correct?
And then was I supposed to include some sort of 'binding' (is that the correct terminology?) to something in the cart/summary? I didn't touch that.
I know I'm doing something wrong that would be very simple for someone who knew what they were doing!
Ah me...