I'm getting an error "Could not find compiled resource bundle 'layout' for locale 'en_US'."

I thought I would update to the latest trunk version of the sdk.  When I run my code I keep getting this Error being thrown:

"Error: Could not find compiled resource bundle 'layout' for locale 'en_US'."

It worked fine with the beta sdk and nightly builds from a long time before that.  The error occured in builds 7573 and 7830, so what ever changed happened before then.  I put a break point in there, and other resource bundles are being loaded ok.

My project uses RSLs and modules. I'm using Flash Builder beta.

I'm not familiar with resource bundles and not sure what to look for.  Any ideas as to what to try or where to look?

Is there something I need to update to run the latest code?

Is the the appropriate place to post questions regarding the nightly builds?  Or should I be asking somewhere else?

Thanks!

PS Here is the full stack trace if it gives anyone more ideas:

Error: Could not find compiled resource bundle 'layout' for locale 'en_US'.
    at mx.resources::ResourceManagerImpl/installCompiledResourceBundle()
    at mx.resources::ResourceManagerImpl/installCompiledResourceBundles()
    at mx.core::FlexModuleFactory/installCompiledResourceBundles()
    at mx.core::FlexModuleFactory/docFrameHandler()
    at flash.display::MovieClip/nextFrame()
    at mx.core::FlexModuleFactory/deferredNextFrame()
    at mx.core::FlexModuleFactory/update()
    at mx.core::FlexModuleFactory/moduleCompleteHandler()