The problem is, none of the content is viewable without being an authenticated user. RSS readers, like Thunderbird (the greatest unknown RSS reader :-), don't know how to log into Drupal to download the feeds.
Hmmmm, Lets assume for a moment that we are using Basic Authentication instead of Drupal's own. In such a case lots of RSS readers could supply a user and password - possibly even by specifying the URL in the form http://user:pass@www.site.com/path/page Presumably the RSS fetcher understands this format and supplies the username and password when the web server asks for that info. Now - this leads me to wonder whether Drupal authentication and Basic Authentication might be combined somehow - or possibly have a separate page controlled by basic authentication which is internally proxied to the Drupal RSS page. Sorry for the rambling reply :-) Alex