jQuery Grid Plugin - jqGrid

Hello,

I've installed and configured a jqGrid... the grid apprears without any data. I've looked at generated html with firebug. Rows are well filled but hidden. I have found a workarround : 

$('#table').jqGrid({

    url:'/get_grid_data',
    datatype: "json",
    mtype: 'GET',
    colNames:['Numéro','Client', 'Date','Paiement','Livraison','Etat facturation'],
    colModel :[
      {name:'numero', index:'numero', width:55, search:true, stype:'text'},
      {name:'client', index:'client', width:150, sortable:false},    
      {name:'date', index:'date', width:90},
      {name:'paiement', index:'paiement', width:80, align:'right'},
      {name:'livraison', index:'livraison', width:80, align:'right'},
      {name:'etat_facturation', index:'etat_facturation', width:80, align:'right'},
    ],
    width:910,
    pager: '#pager',
    rowNum:10,
    rowList:[10,20,30],
    sortname: 'numero',
    sortorder: 'desc',
    viewrecords: true,
    caption: 'Commandes',
    loadComplete: showTable

});

function showTable ({$('#table').show();)

This way, the table behavior is norma; datas appearsl. But I would like to understand why rows are hidden to avoid using this hack.

Thanks for for your help