I have two WordPress 2.7 installs on a website. Both are configured in exactly the same way (one is private, the other is public). The private install has a correctly working RSS sidebar widget. It shows the latest three blog entries. When you go directly to the RSS feed by clicking on the link, all entries are shown in a newest->oldest fashion.
The public install does things differently. The sidebar widget displays the 3 oldest blog entries. When you go to the feed directly, it shows them in the correct order.
The link to see this in action is: http://www.presstaging.com/blog/
The link directly to the RSS feed is http://www.presstagingresourcecenter.com/blog/feed
Hopefully somebody is able to help me figure this out.