Index: invite.module
===================================================================
--- invite.module	(revision 621)
+++ invite.module	(working copy)
@@ -868,7 +868,7 @@ function invite_form_validate($form_id, 
         $error = format_plural(count($failed_emails), 'The following recipient is already a member:', 'The following recipients are already members:') .'<br />';
         foreach ($failed_emails as $key => $email) {
           $account = user_load(array('mail' => $email));
-          $failed_emails[$key] = theme('username', $account) .' ('. check_plain($email) .')';
+          $failed_emails[$key] = t('!username (@email)', array('!username' => theme('username', $account), '@email' => $email));
         }
         $error .= implode(', ', $failed_emails);
         drupal_set_message($error, 'error');