$_SERVER['REQUEST_URI'] giving wrong Location

I have created a 404 error page using PHP and .htaccess. The page comes up like it is supposed to, but the variable $_SERVER['REQUEST_URI'] outputs the 404 error page instead of the page that was called first. The code is:

Page name: &lt;<?php echo htmlentities( $_SERVER['REQUEST_URI'] ); ?>&gt;

ex. If I was going to the page http://mysite.com/aboutUs.htm and the page does not exist the 404 Error page will come up and the request uri variable outputs http://mysite.com/404error.php How do I get it to display the correct uri?
Thanks
Mathius

it could be a server issue... I wrote an article for devarticles.com and a few people had that same problem...

some replies here might help?
http://forums.devarticles.com/showthread.php?threadid=765