Why is there all this extra white space?

This is the page I am having trouble with:

https://vistarewired.com/2007/03/13/have-windows-update-display-the-updates-you-really-need/

I have trouble understanding why there is so much white
space between the article and the comments section.

It’s not because of the googleads because I’ve tried removing them. Below is the code for single.php
Can someone please help me? thanks.
Btw, i’ve taken out the google code

<?php get_header(); ?>

<div id=”content”>

<div id=”maincontent”>

<div class=”post”>

<?php include (TEMPLATEPATH . ‘/theloop.php’); ?>

<center>

</center>

</div><!– end .post–>

<?php include (TEMPLATEPATH . ‘/rsidebar.php’); ?>

<div class=”clear”></div>

<?php if (function_exists(‘paged_comments_template’)) paged_comments_template(); else comments_template(); ?>

</div><!– end #maincontent–>

<?php get_sidebar(); ?>

</div><!– end #content–>

<?php get_footer(); ?>