It's just a small typo:
require/wol/WakeOnLan.php returns true so the following is working 
ms_computer.php
//Wake On Lan function
       if ($wol->wol_send == $l->g(true)) {
            msg_info( $l->g(1282).$wol->wol_send . "=>" . $wol_item->MACADDR . "/" . $wol_item->IPADDRESS);
        } else {
            msg_error($l->g(1282).$wol->wol_send . "=>" . $wol_item->MACADDR . "/" . $wol_item->IPADDRESS);
        }
instead of
    if ($wol->wol_send == $l->g(1282)) {
            msg_info($wol->wol_send . "=>" . $wol_item->MACADDR . "/" . $wol_item->IPADDRESS);
        } else {
            msg_error($wol->wol_send . "=>" . $wol_item->MACADDR . "/" . $wol_item->IPADDRESS);
        }