HTML - Wide Abstracts

Hello,

Mozilla Firefox is doing some weird things to the content of my website (you can see it at http://www.mm-theory.com). What it does is, every so often, it widens some of the content of the page so that it spans from the very left edge of the table cell it's in to the very right edge. A quick refresh usually fixes the problem, but I'm wondering why it does this in the first place.

Here's a few screen captures that shows the problem:

Wide abstract:


Normal abstract:


The captures were taken from http://www.mm-theory.com/god/god.htm

I really doubt it's the code for the abstract since refreshing solves the problem, but here it is anyway:

Code:

</td></tr>
<tr><td class="abstract" colspan=2>

<center>
<table class="abstract" cellpadding=10 cellspacing=0>
<tr><td>
<!-- #include file="../includes/god.abs.inc" -->
</td></tr>
</table>
<br><br>
</center>

</td></tr>

The file god.abs.inc is a plain text file with nothing but text in it (i.e. no code).

I'm thinking it might have something to do with how I close the body of the page since it seems to have to do with not completing properly. Here's the code for that:

Code:

...
</td></tr>
</table>
</body>
</html>

I only encounter this problem in Firefox. Any guesses as to why?