Ok, this is way off the wall but we have had customers complain that they cant checkout. I finally narrowed it down to the fact that something was blowing up with their address during checkout. The actual error was something like "country is not in list of valid countries". Anyway, somehow customers are setting their country to United Stated rather than United States. I have no clue how this is possible as this comes from a dropdown. I checked the db and we had over 800 set that way. Thinking maybe it was a data import issue from when we first went live I just ran a query to set all countries to United States. BAM today we get a customer who can't checkout, I check her address and its United Stated ... run a query and we had 80 more like this just today.
How can the country be getting set improperly?