观察者不保存订单

sales_convert_quote_to_order

public function addLangToOrder($observer){
        Mage::log(\'catching convert_quote_to_order_after\');
        $order = $observer->getEvent()->getOrder();
        $order->setCustomerLanguage(Mage::app()->getStore()->getCode());
        $order->save();
        Mage::log($order->getCustomerLanguage());
    }

<events>
    <sales_convert_quote_to_order>
        <observers>
            <accustomer>
                <type>singleton</type>
                <class>Ac_Customer_Model_Observer</class>
                <method>addLangToOrder</method>
            </accustomer>
        </observers>
    </sales_convert_quote_to_order>
</events>

$customer_lang = \'customer_language\';
$installer->addAttribute(\'order\', $customer_lang, array(\'type\'=>\'varchar\'));