when I test the checkout on your site, i get to the failure page with the following message:
Your transaction could not be completed due to a problem occurring while calculating shipping.
Shipping is not avaliable to the region specified. Please call the office to get a shipping quote and arrange payment or choose a local shipping location to checkout through this site.
Please return to checkout and try again, or contact us.
I am using a US Shipping address, what countries have you configured shipping for?
The failure page uses the following URL variables in the address "shipping=fail&country=false":
to indicate that the failure was due to a shipping rate issue.
Do you also have the same shipping=fail url variable in your test?