Mark Jaquith hat einen Fehler in der aktuellen Wordpress Version gefunden und bietet einen Patch auf seiner Seite an:

Despite two release candidates and several weeks of availability for testing, a bug sneaked into WordPress 2.0.6 that affects the serving of 304 Not Modified feeds. It’s actually related to the Server 500 error issue that 2.0.5 had (and 2.0.6 fixes)… it just affects a different set of people. The solution to one problem caused the other. One symptom of the problem is the following error message from FeedBurner as it tries to request a WordPress 2.0.6 feed:

Your server disconnected us before sending the full source feed content. If your blogging platform is TextPattern, this is a known bug, and a fix can be found here:

http://forum.textpattern.com/viewtopic.php?id=11247

Note that this doesn’t prevent FeedBurner (or anyone else) from fetching your feed 100% of the time. The issue only arises with certain RSS consumers and only on certain servers, and only when the feed attempts to return a 304 Not Modified header. So with FeedBurner, for instance, one fetch attempt may trigger it, but the next will be fine.

Mark on WordPress