Error on checkout3: Index 0 is out of range


Getting this error on a fresh install of umbraco 4.0.3 with commerce4umbraco beta 1.0. Bit of a .net newbie so haven't found a way to debug it. Have looked in windows event viewer and turned umbDebugShowTrace on but not able to see any information about it. I tried copying some of the binaries from the source but I just broke everything. This is running on localhost and I followed the Quick Start instructions as well as setting all the macros to cache for 0 seconds as the default 60 seconds i had for some of them was breaking things. I am trying to purchase 1 unit of A Sample Product, entered a US address and am using Credit Card payment type using my real credit card details. I get the error once I submit the Credit Card details on the checkout3.aspx page and the exact error I get is:

We're sorry, an error occured.
Index 0 is out of range.

Let me know if there is anything I can do my end to give more information about it