Periodic 404 errors and RSS Feed not working

Hello,
My Joomla website, http://www.happyrouter.com, periodically gets 404 errors on the homepage. If I do a refresh, it works the second time. I have checked with my web hosting company and they say that they think it is a .htaccess issue or a php issue. Once I click through the site, everything seems to work fine.

Also, I have been trying to get my RSS feed working for some time. I have installed and uninstalled every RSS feeder for Joomla, usually with the same result. My feed is viewable from Firefox or IE but not viewable/valid when read through a RSS reader (like RSS Bandit) or from feedvalidator.com. Here is the feed link: http://www.happyrouter.com/index.php?option=com_rd_rss&id=1

When going to nwtools.com and doing a HTTP headers verifiction on my website, I also get a 404, like this:
Header are:
HTTP/1.1 404
Date: Wed, 17 Jan 2007 13:19:02 GMT
Server: Apache/1.3.37 (Unix) mod_fastcgi/2.4.2 mod_auth_passthrough/1.8 mod_log_bytes/1.2 mod_bwlimited/1.4 FrontPage/5.0.2.2635.SR1.2 mod_ssl/2.8.28 OpenSSL/0.9.7a PHP-CGI/0.1b
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Expires: Mon, 26 Jul 1997 05:00:00 GMT
Pragma: no-cache
X-Powered-By: PHP/4.4.4
Set-Cookie: PHPSESSID=c5a56e25c6c05124de911d9ca73263bb; path=/
Set-Cookie: 38ddae0312b358432ebc6bdd65727e62=63fc714acef421ac40b9b2e1d4b9a35b; expires=Thu, 18 Jan 2007 01:19:03 GMT; path=/
Set-Cookie: mosvisitor=1
Last-Modified: Wed, 17 Jan 2007 13:19:03 GMT
Connection: close
Content-Type: text/html

Does anyone have any suggestions?? Please help!

Thank you,
David