In the trunk version you have the Log options for the Translation adapter. But then you have have a missing translation it does says which locale has the untranslated message.

My recomended patch is:

Zend/Translate/Adapter.php, row 522 ->

Orginal: if ($this->_options['logUntranslated']) { if ($this->_options['log']) { $this->_options['log']->notice('Untranslated message: ' . $messageId); } else { trigger_error('Untranslated message: ' . $messageId, E_USER_NOTICE); } }

Improvements: if ($this->_options['logUntranslated']) { if ($this->_options['log']) { $this->_options['log']->notice('Untranslated message for '. $locale .': ' . $messageId); } else { trigger_error('Untranslated message for '. $locale .': ' . $messageId, E_USER_NOTICE); } }