encyclo - 2:43 am on Aug 28, 2009 (gmt 0)

it says I should change the mime type because feeds should not be served with the "text/plain" media type. I haven't done that yet (not knowing exactly what to change it to) but I don't think that will solve the problem

It will solve the problem. You need to use the mime type [b]application/rss+xml[/b] for RSS 2.0 feeds - the details of how to achieve this depend on your server environment (the problem is a result of a server misconfiguration).