Having same problem
This is not in direct paypal payments. It is not posting to paypal. Please advise
<input type="hidden" name="shipping_lastname" id="shipping_lastname" value="<?php echo ((isset($_SESSION["eCartCheckoutForm_shipping_lastname"]))?$_SESSION["eCartCheckoutForm_shipping_lastname"]:"") ?>" />
I ended up just using a database because Paypal doesn't get all values I need anyways but would love to see this fixed!