Wish I could help, but I'm not having much luck here either. I don't see this as being "resolved" either, as I'm using WP 2.3.2 freshly downloaded last week, and RSS feeds to my other WP blogs do NOT work.
My first thought was a PHP config setting, allow_url_fopen, but I already have that set to "on". So that's not the issue. Our host does not use any firewalls that would block content, so that's not the issue either.
I have three WordPress blogs on the same server at our host, and I can't link to any of them via RSS feeds. One is a "master" site from which the others spin off, so I like to put the most recent posts from the satellite sites on the home page in widgets.
I cant' link to other WordPress blogs, but I *can* successfully show feeds from forums on other servers (at other hosts) that I visit. And other news sites work. I have the Commentaries area of PC Magazine working in sidebar as well.
One thing I noticed is that the WordPress feeds only show a directory name, where the forum RSS (or Atom) feeds point to actual files or script parameters. (BUT, PC Magazine's feed is just a directory name, and it works!) It's almost amusing that WordPress can't find its own feeds. And yet, all of my WordPress feeds open fine in Feedreader, so they are indeed functional.
If this is indeed a bug, it's like WordPress is not succcessfully "hunting" its own feeds...as all other RSS feeds I'm trying in my sidebars are working.