Paypal payments being processed but no order created

[Joe F]

I'm confused! Set up a new installation recently. When bank deposit orders are placed, they go through fine and show up as orders. However, if the customer selects 'Paypal', they go through the payment process, Paypal charges them, they're returned to the site BUT their customer area shows 'You've made no orders' and no order shows up in the admin area.

I'm using the same Paypal account to receive payments with another Prestashop installation, exactly the same settings as far as I am aware and with no problems.

Thanks for your help!