If a feed contains both an image in the HTML preview and a comment link, and the comment feed finishes loading before the image does, the image will be fetched and displayed twice.
I have several feeds which display this effect, but the most obvious on my feed list is this one:
http://feeds.feedburner.com/stuckincustoms/EmRA?format=xml.
2009-11-21 14:11:49 UTC in Liferea