diff --git a/paypal_payment_ipn/paypal_payment_ipn.module b/paypal_payment_ipn/paypal_payment_ipn.module
index e2f6a0c..ce22742 100644
--- a/paypal_payment_ipn/paypal_payment_ipn.module
+++ b/paypal_payment_ipn/paypal_payment_ipn.module
@@ -35,6 +35,7 @@ function paypal_payment_ipn_post() {
   }
   if (PayPalPaymentIPNController::acknowledge($ipn_variables) && PayPalPaymentIPNController::validate($ipn_variables)) {
     $ipn = new PayPalPaymentIPN($ipn_variables);
+    $ipn->pid = PayPalPaymentIPNController::PID($ipn_variables['invoice']);
     PayPalPaymentIPNController::save($ipn);
     PayPalPaymentIPNController::process($ipn_variables);
   }
diff --git a/paypal_payment_pps/paypal_payment_pps.module b/paypal_payment_pps/paypal_payment_pps.module
index ab3fee7..c60a4b8 100644
--- a/paypal_payment_pps/paypal_payment_pps.module
+++ b/paypal_payment_pps/paypal_payment_pps.module
@@ -251,12 +251,19 @@ function paypal_payment_pps_form_redirect_access(Payment $payment, $account = NU
  * Return callback.
  */
 function paypal_payment_pps_return() {
-  $ipn_variables = $_POST;
-  $payment = entity_load_single('payment', PayPalPaymentIPNController::PID($ipn_variables['invoice']));
-  $ipn = new PayPalPaymentIPN($ipn_variables);
-  $ipn->pid = $payment->pid;
-  PayPalPaymentIPNController::save($ipn);
-  PayPalPaymentIPNController::process($ipn_variables);
+  if (isset($_POST['txn_id'])) {
+    // Make sure this request was not processed before through IPN.
+    $ipn = PayPalPaymentIPNController::load($_POST['txn_id']);
+    if (!$ipn) {
+      $payment = entity_load_single('payment', PayPalPaymentIPNController::PID($_POST['invoice']));
+      $ipn = new PayPalPaymentIPN($_POST);
+      $ipn->pid = $payment->pid;
+      PayPalPaymentIPNController::save($ipn);
+      PayPalPaymentIPNController::process($_POST);
+    }
+  }
+  // (Re)load the payment object to make sure that the object is up-to-date.
+  $payment = entity_load_single('payment', PayPalPaymentIPNController::PID($_POST['invoice']));
   $payment->finish();
 }
 
@@ -266,7 +273,23 @@ function paypal_payment_pps_return() {
  * @return bool
  */
 function paypal_payment_pps_return_access() {
-  return PayPalPaymentIPNController::validate($_POST);
+  // Try to load the Payment object from the returned information.
+  if (isset($_POST['invoice'])) {
+    $pid = PayPalPaymentIPNController::PID($_POST['invoice']);
+    if ($pid) {
+      $payment = entity_load_single('payment', $pid);
+      if ($payment) {
+        // Allow payment method controllers to completely take over validation.
+        if ($payment->method->controller instanceof PayPalPaymentIPNPaymentMethodControllerInterface) {
+          return $payment->method->controller->PayPalValidateIPNVariables($payment, $_POST);
+        }
+        else {
+          return TRUE;
+        }
+      }
+    }
+  }
+  return FALSE;
 }
 
 /**