Pay-Per-View with paypal sandbox - no display of content after paying!

Hi! i tried to test the ppv plugin via paypal sandbox. when clicking on the "pay" button, the paypal sandbox appears and i can login with paypal testaccount. after checking my details i click on "Next" - here should appear a confirmation page from paypal but following happens: paypal window will be closed, i see my content page from wordpress but not the contant i should have pay for.. can anyone help me please asap?