Modify wpsc_have_shipping_quote() to check if a shipping country has been set yet, and if not, default to true.
This is a bit backwards and odd, but given the pain of asking users to update their template files, it makes more sense to return truthy in the scenario where no quotes have been returned due to lack of input, rather than lack of quotes.  Before this change, the shopping cart page would show a non-sensical error on initial load.