wrong address being saved
So...back to the intial problem. I think I have resolved the Billing and Delivery Address issues when paying by credit or debit card however when I purchase with a PayPal account, which is processed successfully, I am taken to the success/confirmation page (checkout_success.php) which displays, somehow, a completely incorrect address. An address that wasn't even entered during the purchasing process because it isn't asked for!
Checking the database, this same address is stored with the order as being the delivery address so there is definitely something wrong with the eCart Store Summary in Database on the PayPal account payments side which is the pp_confirm.php side as far as I understand it.
I've inspected pp_confirm.php and I can't see why this is happening because the behaviour itself is picking up the correct form fields (suffixed with "_2" to indicate that they are the delivery address form fields).
I attach that file, and checkout_success.php (which also seems to be selecting the correct form fields) for inspection, but you also have the FTP details above. Thank you.
EDIT: I ran some testing, my thinking being that maybe because I'd tested a credit/debit card transaction earlier then, somehow, it was storing the billing address entered during that transaction as the delivery address in the PayPal transaction. I cleared cache etc, and ran through another transaction and when I am finally logged in to PayPal to make the payment, it is listing a delivery address there that is the one that's being stored in the eCart Store Summary in Database behaviour so PayPal appears to be sending back a different delivery address than the one that is entered by the customer on our website side.
I'm hoping that will help you track down the issue. Thank you.