Problem with module loading another module

Question

I have run into what appears to be a bug in Adobe Flex 3.3, but would like others opinion.  I have a simple application which loads a module.
If a user checks a box, then the module loads a submodule and calls a funtion in that submodule which modifies the UI slightly.
It really is simple code, but not easy to explain, so bear with me on this :-)  All code is attached.  Rename from *.txt to *.mxml.
I have added an event listener to the submodule loader for the ModuleEvent.READY event so that I can call a function in it once it is loaded (the function modifies the UI):
private function onModuleReady(event:Event):void{     Alert.show(
"Module load successful", "Success");
     if (loader2.child is SubModule) {
          var module:SubModule = loader2.child as SubModule;          module.createCompleteHandler();
          module.modifyUI(pnlMain);
     }else {          Alert.show(
"loader is NOT SubModule", "Failure");     }
Stepping through the debugger, loader2.child IS INDEED a SubModule Class, yet I consistantly step into the else clause.  As I debugged this, I added a similar event listener for the READY even on the loading of the first module.  By just defining a new function in the main module, this code now works.  I don't have to actually call that function, just define it, meaning that if I comment out the entire function onModuleReady (the one defined in the main application that is just printing out a trace), I get the error stated above.
<?xml version="1.0" encoding="utf-8"?><mx:Application 
xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="createCompleteHandler()">
<mx:Script>
<![CDATA[
importMainModule; 
importmx.events.ModuleEvent; 
private function createCompleteHandler():void{loader.url =
"MainModule.swf";
// loader.addEventListener(ModuleEvent.READY, onModuleReady);loader.loadModule();
private function onModuleReady(event:Event):void{ 
if (loader.child isMainModule) { 
trace("here");}
Please try the attached code, and try running it with the function onModuleReady implelented in the Application body and with it removed.  Why would defining a function that is never called for the first module affect the second module?

Answer 1

I figured this out.  I needed to add loader.applicationDomain = ApplicationDomain.currentDomain;
This fixes the problem.