focusManager and Popup with TitleWindow

[mark goldin]

Not sure if this is a bug but here is the situation.
I am creating a popup based on TitleWindow. I am trying to access
focusManager in the following fashion:
trace(UIComponent(control_ID).focusManager);

I am getting null.
Here are two sample files:

TitleWindowTest.mxml
<?xml version="1.0" encoding="utf-8"?>
<!--
http://blog.flexexamples.com/2009/10/23/displaying-a-popup-spark-titlewindow-container-in-flex-4/-->
<s:Application name="Spark_TitleWindow_test"
   xmlns:fx="http://ns.adobe.com/mxml/2009";
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/halo">
<s:controlBarContent>
<s:Button id="btn"
  label="Show TitleWindow"
  click="btn_click(event);" />
</s:controlBarContent>
 <fx:Script>
<![CDATA[
import mx.core.UIComponent;
import mx.managers.PopUpManager;
 protected function btn_click(evt:MouseEvent):void {
var ttlWndw:MyTitleWindow = PopUpManager.createPopUp(this, MyTitleWindow,
true) as MyTitleWindow;
PopUpManager.centerPopUp(ttlWndw);
}
override protected function childrenCreated():void
{
trace(UIComponent(textinput).focusManager);
}
]]>
</fx:Script>
<s:TextInput id="textinput"/>
</s:Application>

MyTitleWindow.mxml
<?xml version="1.0" encoding="utf-8"?>
<!--
http://blog.flexexamples.com/2009/10/23/displaying-a-popup-spark-titlewindow-container-in-flex-4/-->
<s:TitleWindow name="MyTitleWindow"
   xmlns:fx="http://ns.adobe.com/mxml/2009";
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/halo"
   title="Spark TitleWindow title"
   width="300" height="200"
   close="ttlWndw_close(event);">
 <fx:Script>
<![CDATA[
import mx.core.IFlexDisplayObject;
import mx.events.CloseEvent;
import mx.managers.PopUpManager;
import mx.core.UIComponent;
protected function ttlWndw_close(evt:CloseEvent):void {
PopUpManager.removePopUp(evt.currentTarget as IFlexDisplayObject);
}
override protected function childrenCreated():void
{
trace(UIComponent(textinput).focusManager);
}
]]>
</fx:Script>
<s:TextInput id="textinput"/>
</s:TitleWindow>

Works fine in the main file, but not in the popup.

Thanks for help.