Are you using PAYPAL ?? We used PayPal for orders from P&C. P&C dutifully called and confirmed we were the appropriate age. Then after a couple weeks, PayPal would not let a transaction go through. It said there was a Federal Investigation something or other and made no mention of tobacco. So we used debit after that with no trouble so far. We have AT&T broadband. Even with the Fed notification, it showed the transaction pending.
My guess is there is wire transfer network tracking going on for overseas transactions and the Feds (I hope) are just making sure these are not terror related. If you think about it, we are from all over the world and spend lots of money in an interconnected hub of tobacco companies and some of us fleabay. If one of us has any dubious habits then everyone connected will be looked into.
But then maybe its your computer. Sorry I don't know how to help, except check for virus or bots.