EDIT: Due to the answer I change the code posted. I\'ve added the Security.allowDomain(\"*\") line and that line throws me an error. So, ho
Security.allowDomain(\"*\")
Assuming that the external SWF is also in the application directory, you could try loading it using the app:/ scheme:
app:/
var urlRequest:URLRequest = new URLRequest("app:/path/application.swf");
That may put it into the same security context as the main application.