The watchdog function in drupal 6 already includes the translation of a message.

The watchdog function in drupal 6 already includes the translation of a message. Therefore it should not be called like its done for example in civicrm_group_roles.module:

$msg = t('Error: Unable to sync role @role', array('@role' => $role) );
watchdog('civicrm_group_roles', $msg);
if ($debug_mode) drupal_set_message($msg);

instead it should be more like:

$msg = 'Error: Unable to sync role @role';
$variables = array('@role' => $role);

watchdog('civicrm_group_roles', $msg, $variables);
if ($debug_mode) drupal_set_message(t($msg, $variables));

See api documentation: http://api.drupal.org/api/function/watchdog/6