not sure if anyone else has noticed this? i got a complaint from customer last week that her valid credit card number was being rejected as invalid by ShopSite Shopping Cart. i just ran into it tonight when trying to enter an order on behalf of a customer. the card is not rejected when you click on "proceed to confirmation" out of the Check Out page, but when you click on "submit" from the Confirmation page, the error message occurs.
now maybe this is a freak coincidence of 2 cards in the few days since upgrade, and never a problem reported before...but just checking?