We sell publications from our website and our shopping cart appears to be malfunctioning. At times the shopping cart appears frozen and will only accept 1 product in it and not more than that; at other times it is "frozen" and has 1 product in the cart and will not accept others. We are unsure why this happens. whether it involves a hack or malfunction. We want to know why it is happening and of course to fix it. it is a custom built shopping cart.