Checkout error when selected shipping method is not available for validated address

[rsisco]

When a customer has provided an address during the shipping method step of checkout that is then changed by the address validation to an address that is not approved for the selected shipping method, a Magento exception is thrown with no clear instructions for the customer to remedy the problem. This can occur when the address validation service returns an address that differs from what the shipping carrier says is valid. For example, in an area where the zip code boundaries have been adjusted and either the AvaTax validation service or the carrier's rate calculation code has not been updated, AvaTax will say the zip code should be XYZ123, but the carrier says no rates are available because it expects a zip code of 123XYZ..

Preconditions

1. A shipping method is enabled that is unavailable for specific or invalid addresses

Steps to reproduce

1. Add one or more physical products to the cart and proceed to checkout
2. Provide an address that is valid for the shipping method, but that AvaTax will provide a suggested replacement for (my example is a private residence, so I will not publish the address here)
3. Proceed to the payment method step

Expected result

1. I will see the payment method step with the originally provided and suggested revised shipping addresses

Actual result

1. I receive a cryptic error message from Magento
   

[rsisco]

This has been resolved in release #1.4.2 via a more verbose and informational error message.