--- uc_authorizenet.module (2224)
+++ uc_authorizenet.module (2225)
@@ -353,6 +352,7 @@
         'success' => FALSE,
       );
       $comment[] = '('. $response['resultCode'] .': '. $response['text'] .')';
+      uc_order_comment_save($order->order_id, $user->uid, implode('<br />', $comment), 'admin');
     }
 
     // Transaction succeeded.
@@ -398,7 +398,7 @@
           'amount' => _uc_authorizenet_format_amount($amount),
           'customerProfileId' => $profile['customerProfileId'],
           'customerPaymentProfileId' => $profile['customerPaymentProfileId'],
-          'customerShippingAddressId' => $profile['customerAddressId'],
+          'customerShippingAddressId' => (!empty($profile['customerAddressId'])) ? $profile['customerAddressId'] : '0',
           'order' => array(
             'invoiceNumber' => $order->order_id,
           ),