Flex module no more a module when extended?

I have created a module in Flex like below:

modules/ModuleBase.mxml

<?xml version="1.0" encoding="utf-8"?>
<mx:Module xmlns:mx="http://www.adobe.com/2006/mxml">
 // components here
</mx:Module>

So far so good - when this file is saved ModuleBase.swf is generated.

Now I extend the above and create another class:

ModuleChild.mxml

<?xml version="1.0" encoding="utf-8"?>
<ModuleBase xmlns="modules.*" xmlns:mx="http://www.开发者_StackOverflow社区adobe.com/2006/mxml">
    // more components here
</ModuleBase>

Now, What I had expected was for Flex Builder to generate ModuleChild.swf. Which doesn't really happen. Bummer.

What am I doing wrong here?

After testing for sometime figured out the solution:

1. Right click your project and select properties
2. Click Flex Modules in the left menu
3. Find your module, select it and Edit
4. In Optimize SWF size select Do not Optimize
5. Be happy :)