/**
  * Check if order item can be refunded
  *
  * @param Mage_Sales_Model_Order_Item $item
  * @param array $qtys
  * @param array $invoiceQtysRefundLimits
  * @return bool
  */
 protected function _canRefundItem($item, $qtys = array(), $invoiceQtysRefundLimits = array())
 {
     $result = parent::_canRefundItem($item, $qtys, $invoiceQtysRefundLimits);
     if ($vendorOrder = Mage::registry('vendor_order')) {
         return $result && $vendorOrder->getVendorId() == $item->getVendorId();
     } else {
         return $result;
     }
 }