to transform the widget that displays the "latest members" to"last connected", edit the file ow_system_base/bol/user_dao.php line 182 change the query
$query = "SELECT `u`.*
FROM `{$this->getTableName()}` as `u`
{$queryParts["join"]}
WHERE {$queryParts["where"]}
ORDER BY " . ( !empty($queryParts["order"]) ? $queryParts["order"] . ", " : "" ) . " `u`.`joinStamp` DESC
LIMIT ?,? ";by
$query = "SELECT `u`.*
FROM `{$this->getTableName()}` as `u`
{$queryParts["join"]}
WHERE {$queryParts["where"]}
ORDER BY " . ( !empty($queryParts["order"]) ? $queryParts["order"] . ", " : "" ) . " `u`.`activityStamp` DESC
LIMIT ?,? ";Test on 1.7.1