Missing closing li tag after nested lists

Hello,

My HTML validator keeps catching this error, and while it seems to have no critical affect on the usability of the module, my boss likes to see HTML error-free sites. (Meaning I need to somehow fix it). Anyhow, so when TOC creates a nested list under the main headers, it misses the closing </li> tag after the closing </ul> tag.

Example: (copied and pasted from my source code)

<ul>
	<li class="toc-level-1"><a href="#Overview">Overview</a></li>
	<li class="toc-level-1"><a href="#How_it_Works">How it Works</a></li>
	<li class="toc-level-1"><a href="#Demo">Demo</a></li>
	<li class="toc-level-1"><a href="#Instructions">Instructions</a>
<ul>
	<li class="toc-level-2"><a href="#Configuration_Variables">Configuration Variables</a></li>

</ul> //needs to have a closing </li> tag here
	<li class="toc-level-1"><a href="#Suggested_File_Names">Suggested File Names</a></li>
	<li class="toc-level-1"><a href="#File_Permissions">File Permissions</a></li>
	<li class="toc-level-1"><a href="#Valid_HTML">Valid HTML</a></li>
	<li class="toc-level-1"><a href="#Robot_Exclusion">Robot Exclusion</a></li>
	<li class="toc-level-1"><a href="#Cascading_Style_Sheets_CSS">Cascading Style Sheets (CSS)</a></li>
	<li class="toc-level-1"><a href="#Adding_RSS_Feeds">Adding RSS Feeds</a></li>

	<li class="toc-level-1"><a href="#Related_Links">Related Links</a>
<ul>
	<li class="toc-level-2"><a href="#Helpful_HTML_links">Helpful HTML links</a></li>
	<li class="toc-level-2"><a href="#Helpful_Stylesheet_links">Helpful Stylesheet links</a></li>
</ul>
</li> //but it does have one here?
</ul>

I'm not sure if this is an error in the module, or maybe is it something funny with my headers? Either way, if anyone has a solution it would be greatly appreciated.
Thanks,
Emily