If I call myGrid.render() when container's display style is set to 'none' all data is normally rendered, but header is not. Is this the correct behavior?

part of my code:

<div id="grid_example" style="display: none; height: 150px;">

<script type="text/javascript">

var myColumns = [
{header: "Col 1", width: 200, sortable: true},
{header: "Col 2", width: 400, sortable: false},
{header: "Col 3", width: 75, sortable: false}
var columnModel = new YAHOO.ext.grid.DefaultColumnModel(myColumns);

var myData = [
var dataModel = new YAHOO.ext.grid.DefaultDataModel(myData);

var ExGrid = new YAHOO.ext.grid.Grid('grid_example', dataModel, columnModel);


document.getElementById('grid_example').style.display = 'block';
tks, those extesions are remarkables!