title: django-paypal setup for paypal web site pro (wpp) signal issues
body: <p>I'm using dcramer's fork of django-paypal and I've been successful in setting it up until now. I tried to connect 'paypal.pro.signals.payment_was_successful' to a listener I wrote but it sends the signal multiple times which is causing errors in my application. I've tried adding the 'dispatch_uid' to my connect statement but it still sends it multiple times... What am i doing wrong? Should I even be using this signal? </p>