Heather,
I think you might be correct with the difference being https and http because I tried to access them both in my browser and the https gave me a certificate error. The catch I'm having now, in order to test this out, is that I don't see "portalurl" in my config.xml. Could this be located in another file location? I see "portalurl" alot on the PortalBasemapAppender.as but no specific URLs are referenced.