A really strange one. My RSS feed does not come out as XML and fails at http://validator.w3.org/. The error says: “It looks like this is a web page, not a feed. I looked for a feed associated with this page, but couldn’t find one.”
If I look at the output of http://blog.dailysqueezer.com/?feed=rss2 it does indeed look like html and not like the xml your blog RSS feed generates.
Can this be theme related?