title: Can Paypal IPN payment_status change from Completed into another status for a transaction?
body: <p>If I have received an IPN that tells me the transaction (txn_id=123) is completed (i.e. payment_status=Completed).</p>
  
  <p>Is this possible that for some reasons I will later receive another IPN that tells me the payment_status of the same transaction (txn_id=123) has changed from "Completed" to another status.</p>
  
  <p>Anyone has experience with this?</p>
  
  <p>Many thanks to you all.</p>