// Perform database queries to gather online user lists.  We use s.timestamp
  // rather than u.access because it is much faster.
  $anonymous_count = sess_count($interval);
  $authenticated_users = db_query('SELECT DISTINCT u.uid, u.name, s.timestamp FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.timestamp >= %d AND s.uid > 0 ORDER BY s.timestamp DESC', $interval);
  $authenticated_count = 0;
  $max_users = variable_get('user_block_max_list_count', 10);
  $items = array();
  while ($account = db_fetch_object($authenticated_users)) {
    if (!isset($items[$account->uid])) { ///<<< доп. условие
      if ($max_users > 0) {
        $items[$account->uid] = $account; /// <<< было $items[], стало $items[$account->uid]
        $max_users--;
      }
      $authenticated_count++;
    }
  }

  // Format the output with proper grammar.
  if ($anonymous_count == 1 && $authenticated_count == 1) {
    $output = t('There is currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', 'count users'), '%visitors' => format_plural($anonymous_count, '1 guest', 'count guests')));
  }
  else {
    $output = t('There are currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', 'count users'), '%visitors' => format_plural($anonymous_count, '1 guest', 'count guests')));
  }

  // Display a list of currently online users.
  $max_users = variable_get('user_block_max_list_count', 10);
  if ($authenticated_count && $max_users) {
    $output .= theme('user_list', $items, t('Online users'));
  }

  $block['subject'] = t('Who\'s online');
  $block['content'] = $output;
}