Paypal - After Payment has been submitted...

I have setup Membership plugin on my blog and it seems to be working ok except finalizing the checkout procedure with paypal.

The site redirects me correctly to the paypal's payment processing screen and Im able to finish the transaction but paypal is not redirecting me back to my blog nor the transaction is being added to the payment gateway under View transactions nor the user account is being updated with the new subscription I just purchased.

any ideas?