Flex AIR custom utility window won't restore with main app window

Question

I'm trying to add a custom window to the main app window without creating a new taskbar item

<mx:Window xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="400" height="300" title="Window2" showFlexChrome="false" systemChrome="none" type="utility"> <mx:Label x="164" y="154" text="Test" width="173" height="21"/> </mx:Window>

and then to create it in the main app

var mainWindow:Main = new Main();
mainWindow.open();

which works but if the app is minimised and then restored it will only bring back up the main window, not the custom utility window? Am I going about this the wrong way?