Using their PHP RSS code you will see:
Warning: fopen(http://www.sitepoint.com/rss.php): Failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in D:\InetPub\vhosts\wiserway-4249.package\wiserways.net\wwwroot\webtech\presentations\rss\sitepoint.php on line 187
Error reading RSS data.