Missing WindowedApplication chrome on Flex4 + AIR 2.0beta2

I've installed the Flex 4 SDK and overlayed it with 开发者_运维知识库the AIR 2.0beta2 SDK and am unable to bet the Flex chrome to show up when I try to use Spark's WindowedApplication.

the simple MXML -> http://pastie.org/909375

When I use the MX WindowApplication everything works fine, but somehow I'm not getting the Spark version to work as I expect.

What am I doing wrong?

Jon

WindowedApplication {
   skinClass:ClassReference("spark.skins.spark.SparkChromeWindowedApplicationSkin");  
}