I'm seeing a problem with RSS Feeds not working. I don't know how to duplicate it, but it does show up in the TwentyEleven Theme with all plugins disabled.
The problem is:
I setup the RSS Feed widget to show all posts from a specific category. It works fine initially ...then I come back at some later time and add a post to this category but that new post does not show up in the list of RSS feeds. Any idea what the problem is?