In my experience, the new 188.8.131.52 version of the RSS Feed Reader errors out any time I ask it to render an RSS feed directly from a list or library. The old "smiling goat" 2.0 versions rendered both standard rss feed urls and wss urls.
does not appear to be
a valid RSS feed. If the feed is valid, please ensure your proxy server settings are correct if you use a proxy server.
Error returned from FeedReader: The remote server returned an error: (401) Unauthorized.:SmilingGoat.Syndication"
is the error I am shown in the web part itself after applying the address listed to the Feed List properties.
I sent Tim copies of the screenshots showing both how the old part renders this address fine and the new one displays the error.
Thanks for looking into this.