Paypal Pro PCI :: Transaction cannot be processed. Please use a different card

I set up a form to sell tickets, most of the time the payment goes through fine, but once in a while i get a client who tells me that no matter what card is used, they get a message saying PCI :: Transaction cannot be processed. Please use a different card. This doesn't happen every time, only 1 of 20 or so. Please advise on this.

This error is related to the transaction being declined by the bank. Could be a bad CVV value, bad billing address, bad expiration date or other cause.