HTML:
<dl class="secondaryContent">
<h3>Media Navigation</h3>
<ol class="categoryList">
<li>
<a class="selected" href="media/">Media Index</a>
</li>
<li>
<a href="search/?type=xengallery_media">Search Media</a>
</li>
<li>
<a href="find-new/media">New Media</a>
</li>
</ol>
</dl>
This probably should be <div class="secondaryContent"> rather than <dl class="secondaryContent">, as the childs of a DL element must be DD or DT elements.
Possibly applies as well to the additional sidebar blocks of the gallery.