New Post: the Cart is not empty, the order not cleared

Hello, thank you thousand times for your job...

Paypal is receiving the payment, redirects to the checkout page, but you can read "Your basket is empty. - Return to store", clicking on the menu Store and Checkout pages link, you realize that the order is not gone away from the cart...
In the admin store, payment are marked 'ok', and money are actually going where they have to go...
only, the customer is not redirected to the 'thank you for your payment' page, and the order seems to want to remain forever...:)
I've tried to understand, but I do need help

thank you