My debit card wouldn't go through a purchase during the Olympics in London. I called up my bank and told them that I knew who I was dealing with as I have made purchases from them before and asked them to please cut off their block. I haven't had any problems since.
They started doing this as a preventative measure. They often block purchases in California and other places because of fraud problems too. Just be nice and ask them to back off. Any more you even have to notify your bank if you take an out of state trip and let them know where you may be going and how long you'll be gone. It really is for your protection.