Code Igniter Session problem

[eluser]Unknown[/eluser]
yes! IE is set to accept cookies. and i told earlier that the system is running fine in IE in my local machine but the problem occurs on the client server.

let me show you the code..

i have a model name Login

Code:

class Login extends Model
{
   var $isAuth = false;

   function Login()
   {
      parent::Model();
   }

   function authenticate()
   {
      ...........;
      ...........;
      if($isAuth){
         $userdata = array(
           'userid'=> $recordSet->userid;
           'role'=> $recordSet->role;          
         );
         $this->session->set_userdata($userdata);
         ..............;
         ..............;
      }
   }
}

From a controller class i am trying to pull some data

Code:

class Members extends Controller
{
   function Members()
   {
       parent::Controller();
   }

   function showMemberData()
   {
       $this->db->where("userid", $this->session->userdata("userid"));//this line fails as it couldnt retrieve the userid in IE in my client server.
       $query = $this->db->get("users");
       .......;
       .......;
   }
}

Any idea about this?