Can't Get the Store Tab Added on Facebook

I'm sure that I made a mistake somewhere along the way, but I'm actually running into two problems.

Problem 1: I've gone through the setup steps over and over, and I cannot get the Store tab to appear on my Facebook Page. Here's a screenshot of as far as I seem to be able to get to adding the tab to my Facebook page: http://disdads.com/media/salescart/SalesCartFacebookFail.png

The page I'm trying to add the tab to is here: https://www.facebook.com/disdadspodcast/

Problem 2: I was primarily focused on getting the store up and running on our website last night. I thought I had it all working pretty well - a few products added and ready for people to place orders. But when trying to test the ordering system, the account registration system appears to be having problems. When I log in as a "Returning User" with the test account I set up last night. This is the initial screen after the login:
http://disdads.com/media/salescart/ReturningLogInProblem.png

It's possible that's the way it's supposed to handle a returning user, but for the user, that's very confusing. It suggests that they haven't completed their registration, but also says Welcome Back!

From there, clicking through Store Top will get the returning user into the store.
And the returning user can add an item to the Shopping Basket and even begin the checkout process. But when the user clicks through to the "Shipping" item (which is largely unnecessary, since I've chosen to include the shipping cost in the price of the items), we're brought to a screeching halt with this error. (I suspect it's a configuration confusion issue on my part, just not sure what setting I need to change).
http://disdads.com/salescart/ShippingError.png

Any assistance you can provide in helping me get these issues resolved would be greatly appreciated. I'm REALLY trying to get this small store up and running for this weekend's holiday shopping.