The cart going to PayPal only works with the default [Price] * [Quantity] setting. Adding shipping to the calculation brings - Sorry... Transaction Failed. Cart price does not match content. something like that. Now... the cart is getting sent to PayPal but ignoring the shipping calculation.
$ATC_itemPrice = floatval("1.00");// column binding
$ATC_itemShipping = floatval("1.00");// column binding