Index: in-commerce/units/gateways/gw_classes/sella_guestpay.php
===================================================================
--- in-commerce/units/gateways/gw_classes/sella_guestpay.php	(revision 15437)
+++ in-commerce/units/gateways/gw_classes/sella_guestpay.php	(working copy)
@@ -89,7 +89,7 @@
 		function processNotification($gw_params)
 		{
 			$a = $gw_params['merchant_id'];
-			$b = $_REQUEST['b'];
+			$b = $_GET['b'];
 			$url = 'https://ecomm.sella.it/CryptHTTPS/Decrypt.asp?a='.$a.'&b='.$b.'&c=2.0';
 
 			$curl_helper = $this->Application->recallObject('CurlHelper');