FxSpinner with wireframe skin does not resize properly

Steps to reproduce:
1. Compile with the following argument (to use the wireframe skins):
-theme=C:\FlexBuilds\trunk\4598\flex_sdk_4\frameworks\themes\Wireframe\wireframe.swc

<?xml version="1.0" encoding="utf-8"?>
<FxApplication backgroundColor="0xFFFFFF" xmlns="http://ns.adobe.com/mxml/2009" height="600">
<VGroup>
<FxSpinner id="spin" height="100" />
<FxTextArea id="ta" text="Text Area" />
</VGroup>
</FxApplication>

Actual Results:
Notice how the FxSpinner sizing is grossly incorrect. Only the bottom button resizes.

Expected Results:
FxSpinner should resize correctly. If you don't use the wireframe skin it looks as expected.

Workaround (if any):