WP HTTP Error: couldn't connect to host for RSS feeds on same domain

I'm having trouble reading RSS feeds created by WP3 on the same domain.

When I do a print_r($rss); at the part of my plugin where it does the RSS parsing, I get the following output:

WP_Error Object ( [errors] => Array ( [simplepie-error] => Array ( [0] => WP HTTP Error: couldn't connect to host ) ) [error_data] => Array ( ) )

The RSS feed address being supplied validates and everything, btw.

It seems to me the issue has something to do with the webserver being unable to grab its own RSS feeds. This is all very confusing. There's a blog post that seems to identify the issue at: http://www.ajaykumarsingh.com/wordpress/rss-error-wp-http-error-couldnt-resolve-host.html

...Alas, it does not contain any solutions.

Any ideas for a workaround would be much appreciated.