You have an HTML error here
Code:
<div id="indexDefaultMainContent" class="content"><a href="http://www.lulu.com/content/466605"><img src="images/large/default_header.jpg"
</div>
Missing closing tags /></a> :
Code:
<div id="indexDefaultMainContent" class="content"><a href="http://www.lulu.com/content/466605"><img src="images/large/default_header.jpg" /></a>
</div>
Different handling of errors is a prime cause of different browser results (right after IE bugs:).