Fatal error: Call to a member function insert() when using active records in CodeIgniter

When i try to access the database using CodeIgniters Active records it always gives me the error

Fatal error: Call to a member function insert() on a non-object

Fatal error: Call to a member function get() on a non-object

below is the settings in my database

$active_group = 'default';
$active_record = TRUE;


$db['default']['hostname'] = 'localhost';
$db['default']['username'] = 'root';
$db['default']['password'] = '';
$db['default']['database'] = 'test';
$db['default']['dbdriver'] = 'mysql';
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = TRUE;
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;

$db['default']['cachedir'] = '';
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;

and i have auto-loaded it

$autoload['libraries'] = array('database','session');

and below is my model

class Leads_model extends CI_Model {

function __construct()
  {
    parent::__construct();

  }

    function insertq(){

        $q=$this->db->insert('test',$data);

        if ($q){

            return true;
        }       

        else
        {
            return false;
        }


    }
}

can someone please suggest me what am i doing wrong and why am i getting that error?

Answer

The problem was i had added some variables to get the autocomplete work in to the model core. That was causing the problem and its working after removing those.

but the auto complete doesn't seem to work now.