It is going to give that warning any time a transaction fails. It posts the failure reason to the page and since it comes from paypals https:// server it will give you that warning as it returns to your server without SSL. Getting a SSL certificate would resolve the problem.
I think the error you are getting is because you aren't putting in a valid florida shipping address. It actually evaluates that the zip code and city you enter matches the state. If you put in a full and valid florida address the payment works properly.