public function _fixFieldData()
    {
        $fieldMap = $this->getTrackEngine()->getFieldCodes();

        foreach ($this->_fieldData as $key => $value) {
            if (isset($fieldMap[$key])) {
                // The old name remains in the data set of course,
                // using the code is a second occurence
                $this->_fieldData[$fieldMap[$key]] = $value;
            }
        }
    }