I follow http://gingerhaze.com/nimona/rss.xml in a comics dedicated folder, and for the past few weeks whenever there is an update it gets stuck showing me old entries.
Glancing thru the XML, the feed seems to updating properly so it seems like a problem on your end?
While we’re at it, same thing happens with http://drmcninja.com/feed/ - keeps showing me an old entry on new updates. I’ve only really noticed this on my comics feeds, hence the particular feeds.