I tried the fix to standard.tpl as shown above - However, It didn't work. Paypal (sandbox) shows the order as completed, but order never completes in Prestashop.
I'm running:
PayPal USA, Canada v1.3.9 - by PrestaShop ( Standard Payments, in Test (Sandbox) mode )
PrestaShop version 1.6.1.3
PHP version 5.5.32
Any thoughts?