Hi Jason . Thanks for your assistance. The shipping element now appears tow work. I'm a little annoyed as to the nature of the error as I was sure that I had replaced all occurrences of Australia Post with AusPost. I will endeavour to check more closer in future.
Sorry but forgot to ask before. I only want to ship to Australia. I therefore want to populate the checkout State form field with valid AUS states not US. I know how to change the drop down values but cannot get them to appear unless the country selected is US.