langsung aja ah gan...
baru berhasil tadi sore...

karena kita pake datatype json jadi kita harus tambahin helper json di codeigniter kita..
Download disini

kopiin isi file donlotannya di "system/helper"

bikin tablenya contoh:

CREATE TABLE `konsep` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`nm_konsep` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=9 DEFAULT CHARSET=latin1;

INSERT INTO `konsep` (`id`,`nm_konsep`) VALUES
(1,'Seni/Budaya'),
(2,'Sejarah'),
(3,'Komunikasi'),
(4,'Profesi'),
(5,'Kuliner'),
(6,'Proses'),
(7,'Go Green'),
(8,'Back To Nature');

Bikin Controller

file controllers/konsep.php

class konsep() extends Controller{
   public function konsep(){
      parent::Controller;
   }
   public function index(){
      load-> vars($data);
      $this->load->view('admin');
   }
   public function getlistkonsep(){
      $sidx = $this->input->post('sidx');
      $sord = $this->input->post('sord');
      $page = $this->input->post('page');
      $limit = $this->input->post('rows');
      $this->load->helper('json');
      $konsep=$this->mkonsep->gridcountkonsep();
      $count=count($konsep);
      if( $count > 0 ) {
         $total_pages = ceil($count/$limit);
      } else {
         $total_pages = 0;
      }
      if ($page > $total_pages) $page=$total_pages;
      $start = $limit*$page - $limit;
      if ($start<0) $start=0;  $row=$this->mkonsep->gridkonsep($sidx,$sord,$start,$limit);
      $response['page'] = $page;
      $response['total'] = $total_pages;
      $response['records'] = $count;
      $response['start'] = $limit*$page - $limit;
      $i=0;
      $rowid=0;
      foreach ($row as $r) {
         $response['rows'][$i]['no']=$r["id"];
         $response['rows'][$i]['cell']=array($r['id'],$r['nm_konsep']);
         $i++;
      }
      echo json_encode($response);
   }
}

Bikin Modelnya

file models/mkonsep.php

class mkonsep() extends Model{
    public function mkonsep(){
        parent::Model;
    }

    function gridkonsep($idx,$ord,$start,$limit) {
  $data = array();
  $this-> db-> select('*');
  $this-> db-> from('konsep');
  $this->db->order_by($idx,$ord); 
  $this->db->limit($limit,$start);
  $Q = $this-> db-> get();
  if ($Q-> num_rows() > 0){
  foreach ($Q-> result_array() as $row){
   $data[] = $row;
  }
  }
  $Q-> free_result();
  return $data;
    }

    function gridcountkonsep(){
     $data = array();
  $this-> db-> select('*');
  $this-> db-> from('konsep');
  $Q = $this-> db-> get();
  if ($Q-> num_rows() > 0){
  foreach ($Q-> result_array() as $row){
   $data[] = $row;
  }
  }
  $Q-> free_result();
  return $data;
    }
}

bikin viewnya

filenya views/admin.php

//di viewnya tambahin css dan javascript yang dibutuhin

//cssnya yg di load

<link rel="stylesheet" type="text/css" href="<?=base_url();?>css/theme/south-street/jquery-ui-1.7.2.custom.css"/>

<link rel="stylesheet" type="text/css" media="screen" href="<?=base_url();?>css/ui.jqgrid.css" />

<link rel="stylesheet" type="text/css" media="screen" href="<?=base_url();?>css/ui.multiselect.css" />



//javascript yg di load

<script type="text/javascript" src="<?=base_url();?>scripts/jquery-1.3.2.min.js"></script>

<script type="text/javascript" src="<?=base_url();?>scripts/jquery-ui-1.7.2.custom.min.js"></script>

<script src="<?=base_url();?>scripts/jquery.layout.js" type="text/javascript"></script>

<script src="<?=base_url();?>scripts/i18n/grid.locale-en.js" type="text/javascript"></script>

<script type="text/javascript">

$.jgrid.no_legacy_api = true;

$.jgrid.useJSON = true;

</script>

<script src="<?=base_url();?>scripts/jquery.jqGrid.min.js" type="text/javascript"></script>

<script src="<?=base_url();?>scripts/jquery.tablednd.js" type="text/javascript"></script>

<script src="<?=base_url();?>scripts/jquery.contextmenu.js" type="text/javascript"></script>

<script src="<?=base_url();?>scripts/ui.multiselect.js" type="text/javascript"></script>



//dan ini untuk menampilkan jqgridnya....

<table id="list2"></table>

<div id="pager2">

</div>



//javascript ini harus di taro setelah table yang diatas itu...

<script type="text/javascript">

   jQuery("#list2").jqGrid({

      url:'admin/getlistkonsep',

      datatype: "json",

      mtype : "post",

      autowidth:true,

      autoheight:true,

      colNames:['id','Konsep'],

      colModel:[

         {name:'id',index:'id', width:55},

         {name:'nm_konsep',index:'nm_konsep', width:90,sortable:false}

      ],

      rowNum:7,

      rowList:[7,14,21],

      pager: '#pager2',

      sortname: 'id',

      viewrecords: true,

      sortorder: "asc",

      caption:"List Konsep"

   });

   jQuery("#list2").jqGrid('navGrid','#pager2',{edit:false,add:false,del:false,search:false});

</script>

untuk pathnya.. di sesuaikan aja ya ma agan2 sekalian hihihi pasti bisa lah :)

sayang ya jqgrid jadi berbayar sekarang :(

good luck...