session library dont retrieve data [on facebook app]

[eluser]Peter74[/eluser]
Hi, i have this problem

my controller

Code:

$data  = array('contenido' => "huge content");
$datos = array('logged_user_id' => $this->uid,
               'currentTab'     => 'uno');
$this->session->set_userdata('datos');
$this->parser->parse('welcome_message',$data);

My View

Code:

$logged_id  =  $this->session->userdata('logged_user_id');
$tab_activo =  $this->session->userdata('currentTab');
$activo1="notcurrent"; $activo2="notcurrent"; $activo3="notcurrent"; $activo4="notcurrent";
   switch($tab_activo){
     case "uno" :    $activo1="current"; break;
     case "dos" :    $activo2="current"; break;
     case "tres" :   $activo3="current"; break;
     case "cuatro" : $activo4="current"; break;              
   }

But the currentTab variable is empty, i need it for set the current navigation var class.

Txs in advance