SecurityDomain problem accessing Adobe Native Extension from Javascript

I have a fairly large project written using Adobe AIR and HTML/Javascript.  I'm trying to test writing an extension using the new ANE stuff.  When I try to load the DLL that I've created I'm getting the error:

Error #2113: Provided parameter LoaderContext.SecurityDomain is from a disallowed domain.

I've tried several different approaches but I've been unsuccessful trying to figure out how to get around this issue.  Any suggestions?

Some detail:

1. In a separate test app I've been able to get straight ActionScript to open and access the DLL.

2. The Javascript is able to talk to the ActionScript using window.runtime just fine (trace statements are output).

3. The error is thrown when I call ExtensionContext.createExtensionContext(...) from my ActionScript code.  My DLL is loaded and the initializer is called (printf debugging).  However the ctxInitializerToSet is never called.

4. My current approach is to have a common ActionScript class which calls the ActionScript library.swf which resides in META-INF/AIR/extensions/<my extension>/META-INF/ANE/<platform>/library.swf and that library is the one attempting to load the DLL.  I've also tried having the common ActionScript file call ExtensionContext.createExtensionContext() directly with similar results.

5. I'm currently attempting this on Mac (so technically it's a framework instead of a DLL) - although I tried Windows at one point too (and the extension is meant to be cross-platform).

Thanks!

- Aaron