Order Total = 0 After The Payment With Paypal

Hi guys, I have a problem that I was not able to fix, please help me!!! :unsure:
If the user makes the order and chooses as a payment method the bank transfer the order total is correct: subtotal + shipping.
Instead, if the user chooses Paypal, the payment is correctly made on the total order (subtotal + shipping) but after payment in administration the total is at 0.
Also the e-mail sent to the customer reports as total 0.
It seems that the order status change from OPEN to PROCESSED, does not pass the information correctly.
Please, help me find the solution! :-)