Typepad

I love Typepad, the ASP service we use to write and publish this Blog.  One of the "cool" features is Domain Mapping. This allows us to change the URL from http://newstex.typepad.com to http://www.newstexblog.com. I have done this many times on other blogs I maintain, but for some reason on this blog the Typelists (Newstex Partners, etc) end up with an error message "[an error occurred while processing this directive]".

This message only shows up when accessing the blog via  http://www.newstexblog.com. I have emailed with Typepad support who seem stumped.  I have disabled the Domain Mapping for them moment until I can do more research on why this is happening? Anyone out there have any ideas?