diff --git a/app/code/community/Bitpay/Bitcoins/controllers/IndexController.php b/app/code/community/Bitpay/Bitcoins/controllers/IndexController.php
index cce944a..be9e720 100644
--- a/app/code/community/Bitpay/Bitcoins/controllers/IndexController.php
+++ b/app/code/community/Bitpay/Bitcoins/controllers/IndexController.php
@@ -23,9 +23,9 @@
 class Bitpay_Bitcoins_IndexController extends Mage_Core_Controller_Front_Action {
 
   public function checkForPaymentAction() {
-    $params = $this->getRequest()->getParams();
+    $params  = $this->getRequest()->getParams();
     $quoteId = $params['quote'];
-    $paid = Mage::getModel('Bitcoins/ipn')->GetQuotePaid($quoteId);
+    $paid    = Mage::getModel('Bitcoins/ipn')->GetQuotePaid($quoteId);
     print json_encode(array('paid' => $paid));
     exit(); 
   }
@@ -33,7 +33,7 @@ class Bitpay_Bitcoins_IndexController extends Mage_Core_Controller_Front_Action
   // bitpay's IPN lands here
   public function indexAction() {
     require Mage::getBaseDir('lib').'/bitpay/bp_lib.php';
-    $apiKey = Mage::getStoreConfig('payment/Bitcoins/api_key');
+    $apiKey  = Mage::getStoreConfig('payment/Bitcoins/api_key');
     $invoice = bpVerifyNotification($apiKey);
 
     if (is_string($invoice))
@@ -52,22 +52,36 @@ class Bitpay_Bitcoins_IndexController extends Mage_Core_Controller_Front_Action
       Mage::getModel('Bitcoins/ipn')->Record($invoice); 
 
       // update the order if it exists already
-      if ($order->getId())
+      if ($order->getId()) {
         switch($invoice['status']) {
+
           case 'paid':
-            $method = Mage::getModel('Bitcoins/paymentMethod');
-            $method->MarkOrderPaid($order);
+            // Mark paid if there is an outstanding total
+            if ($order->getTotalDue() > 0) {
+              $method = Mage::getModel('Bitcoins/paymentMethod');
+              $method->MarkOrderPaid($order);
+            } else {
+              Mage::log('Received a PAID notification from BitPay but there is nothing due on this invoice. Ignoring this IPN.', null, 'bitpay.log');
+            }
             break;
-          case 'confirmed':							
-          case 'complete':					
-            $method = Mage::getModel('Bitcoins/paymentMethod');
-            $method->MarkOrderComplete($order);
+
+          case 'confirmed':
+          case 'complete':
+            // Mark confirmed/complete if the order has been paid
+            if ($order->getTotalDue() <= 0) {
+              $method = Mage::getModel('Bitcoins/paymentMethod');
+              $method->MarkOrderComplete($order);
+            } else {
+              Mage::log('Received a ' . $invoice['status'] . ' notification from BitPay but this order is not paid yet. Possible internal error with Magento. Check order status to confirm.', null, 'bitpay.log');
+            }
             break;
+
           case 'invalid':
             $method = Mage::getModel('Bitcoins/paymentMethod');
             $method->MarkOrderCancelled($order);
             break;
-        }
+         }
+      }
 
     }