my fix around line 768

        // $element[$delta] = array('#markup' => '- ' . t('Private group') . ' -'); // removed
        if($user->uid==arg(1) && arg(0)=='user') {
          // user can see own private group
        }
        else{
          $element[$delta] = array('#markup' => '- ' . t('Private group') . ' -');
        }