One of my users just alerted me that my RSS feed is 6 posts behind my website.

Feed is served directly by the WordPress install (didn't install Feedburner or anything), and located at http://www.thecontradictions.com/feed

I'm not sure how to troubleshoot this. I found this suggestion to use Health Check mode to turn off plugins and see if they are interfering, but if I turn off all the plugins, I can't tell if it's propagating to a user-only RSS feed to double check. Can someone break this down for me a little better?