Try replacing the header table with this:
<table border="0" cellpadding="0" cellspacing="0" id="mainHeader" width="100%">
<tr>
<td align="left">
<a href="http://ariakis.cjb.net/wavpack/#About">About</a><br />
<br />
<a href="http://ariakis.cjb.net/wavpack/#Features">Features</a><br />
<br />
<a href="http://ariakis.cjb.net/wavpack/#Software">Software</a></td>
<td align="center">
<img border="0" src="Images/02.gif" /></td>
<td align="right">
<a href="http://ariakis.cjb.net/wavpack/#Files">Files</a><br />
<br />
<a href="http://ariakis.cjb.net/wavpack/#Archive">Archive</a><br />
<br />
<a href="http://ariakis.cjb.net/wavpack/#Contact">Contact</a></td>
</tr>
</table>
To get the original formatting of the links back, add these two lines to the style sheet (this can be done differently btw, you could try changing the 'a' into a '*' and moving the font-size into that entry for example):
table#mainHeader { font-size: 9pt; }
table#mainHeader a { color: rgb(255,255,255); }
These changes will make this part of the site more conformant with XHTML and much more readable and maintable (unless you like messing with lots of font and span tags, checking whether they're nested correctly, etc.), not to mention smaller.
Also, I'd suggest doing yourself a favour by not using FrontPage. (X)HTML isn't very difficult to learn and creating a page by hand can save you a lot of trouble (=time).
There are some nice editors out there, that generate reasonable code, will leave your code alone if they can and provide a convenient way to access the underlying (X)HTML, but I haven't used one in years so I don't know what is recommended these days. Something like Emacs or anything else that has syntax highlighting will probably also work fine (depending on how easy you find it to work with the raw (X)HTML).
You may also like to run your page through a validator once in a while, especially if you want to use XHTML (it would mostly be a matter of properly closing tags to make it compliant, as far as I can see, as well as changing the DOCTYPE of course).