Payment notification does not work with CBuilder

$pluginsClass = hikashop_get('class.plugins');
		$ppages = new HikashopPPages();
		
		$elements = $pluginsClass->getMethods('payment','securetradingppages');
		
		if(empty($elements) || !isset($elements[1])) {
			$ppages->createException(new Exception('The payment module class could not be retrieved correctly.'), __FILE__, __CLASS__, __LINE__);
		}
		
		$filter = &JFilterInput::getInstance();
		$paymentMethod = $elements[1];
		$postVars = array();
		
		foreach($_POST as $key => $value){
			$key = $filter->clean($key);
			$value = JRequest::getString($key);
			$postVars[$key]=$value;
		}
		
		if (!isset($postVars['errorcode'])) {
			$ppages->createException(new Exception('The errorcode has not been set.'), __FILE__, __CLASS__, __LINE__);
		}
		
		if (!isset($postVars['orderreference'])) {
			$ppages->createException(new Exception('The orderreference has not been set.'), __FILE__, __CLASS__, __LINE__);
		}
		
		if ($paymentMethod->payment_params->usenotificationhash && !isset($postVars['responsesitesecurity'])) {
			$ppages->createException(new Exception('The notification hash is enabled but the reponsesitesecurity was not posted to the notification script.'), __FILE__, __CLASS__, __LINE__);
		}
		
		if (isset($postVars['responsesitesecurity']) && $postVars['responsesitesecurity'] !== hash('sha256', $postVars['errorcode'] . $postVars['orderreference'] . $paymentMethod->payment_params->notificationhash)) {
			$ppages->createException(new Exception('The notification hash is enabled but the responsesitesecurity field did not match the regenerated hash.'), __FILE__, __CLASS__, __LINE__);
		}
		
		$orderClass = hikashop_get('class.order');
		$dbOrder = $orderClass->get($postVars['orderreference']);
		
		if(empty($dbOrder)){
			$ppages->createException(new Exception('Could not load order using orderreference: ' . $postVars['orderreference']), __FILE__, __CLASS__, __LINE__);
		}
		
		$order = NULL;
		$order->order_id = $dbOrder->order_id;
		$order->old_status->order_status=$dbOrder->order_status;
		
		if ($postVars['errorcode'] == 0) {
			$order->order_status = $paymentMethod->payment_params->verified_status;
		}
		else {
			$order->order_status = $paymentMethod->payment_params->invalid_status;
		}
		
		$order->history->history_notified = 1;
		$orderClass->save($order);
		
		exit('Notification Complete.');