You could do with a tidyup of the html coding so that it is closer to fully validating:

HTML Code:
<script language="Javascript" src="http://www.crawlability.com/js/vbseo_menu.js">
should be

HTML Code:
<script language="Javascript" type="text/javascript" src="http://www.crawlability.com/js/vbseo_menu.js">

inserting the following code immediately after the <body>
HTML Code:
<table><tbody><tr><td>
You dont need the height=10 on the lower table
HTML Code:
<TABLE height=10 cellSpacing=0 cellPadding=0 width=500 align=center border=0>
Delete the <br /> from the following
HTML Code:
<li><a href="...">Your Forums Homepage:sitename</a></li>

<br/>
<li><a href="http://www.google.com/webmasters/sitemaps" target="_blank">Your Google Sitemaps Page</a></li>
change it to the following:
HTML Code:
<li><a href="...">Your Forums Homepage:sitename</a><br />&nbsp;</li>

<li><a href="http://www.google.com/webmasters/sitemaps" target="_blank">Your Google Sitemaps Page</a></li>
How about a nicer border and screen layout as well.

When you run the "Site Map Generator"

You currently get a long list of all the activity. How about that list be created inside a frame so that you can have navigation back to the sitemap index page. Or in the very least, a link back to the sitemap index page at the end of the list.

And a nice bold Finished Creating Sitemap - at the end of the list.

Change of Javascript menu

And while you are at it, you have already won the vbulletin.org hack of the month. So how about deleting that from your javascript menu that is hosted at
http://www.crawlability.com/js/vbseo_menu.js