Shipping Defaults to USPS when Using Both Zone Rate and USPS

Hey all ...

We want to use Zone Rates and USPS for Shipping.

Zone Rates will offer a flat $6.50 charge and then FREE Shipping over $100. We also want to have USPS as an option if the customer wants to have the item shipped Priority or Express for faster delivery.

This shows up in the cart properly with the Zone Rate bold as the cheapest rate.
http://platinumnc.com/forumimages/HK-Shipping-001.jpg

But when you go to the cart to checkout, it defaults to USPS Priority.
http://platinumnc.com/forumimages/HK-Shipping-002.jpg

Obviously, we would this to default to the Zone Rate instead of the USPS. Any help that can be offered would be greatly appreciated!

This site uses 1.3.8a and I have installed the USPS patch.

Thanks!