Skin defined in CSS file not found in sub module

Steps to reproduce:
1. Create custom component which uses a custom skin
2. Define component to use the skin via a CSS file defined in a <fx:Style source="main.css"> tag in the main application MXML file.
3. Place the custom component in a separate external Module.
4. Load the external module SWF using the ModuleLoader class, via Actionscript, not via a <mx:ModuleLoader> tag

Actual Results:
Crashes with "Skin not found for custom component"

Expected Results:
Load the custom component using the skin defined in the main CSS file

Workaround (if any):
Using <mx:ModuleLoader> seems to fix it. Sometimes using setStyle("skinClass") will fix it...but not always?

Flex SDK: 4.1.0.14570
Flash Builder: 4.0 build 271588

This problem does not occur in the Gumbo Beta 2 SDK version. So I believe it is a regression.

Attached is a sample project reproducing the problem...Sorry for so many files, couldn't find a smaller way.

1. ModuleSkinTest.mxml - main application file
2. main.css - links skin to custom component
3. ChildModule.mxml - sub module that gets loaded by main application
4. TestComponent.as - custom component placed inside sub module
5. TestComponentSkin.mxml - custom skin for custom component
6. ModLdr.as - Custom AS logic for loading the sub module