Taxonomy_dhtml no longer works with 4.7.2 and Internet Explorer

It looks like the disappearance of links is related to my theme some way (a custom theme). I still get the error under Bluemarine, but I'm not sure it hurts functionality at all... you might be fine even with this error occuring...

In the meantime, if anyone has any idea why my theme breaks the presentation of taxonomy_dhtml, I would appreciate any advice or solutions. The headings for each category are also missing! Here's the output of the html from IE:

 <!-- start main content -->
      <!-- begin content --><div class="voc">
<h3>groups</h3>
<ul class="menuList" id="menu_">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_', 'actuator'));
  } 
</script>
<li class="menubar"><a href="/alpinecounty/taxonomy/term/272/9" title="" class="actuator" id="actuator1">departments (134)</a></li>
<ul class="submenu" id="menu_1">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_1', 'actuator1'));
  } 
</script>
<li class="menubar"><a href="/alpinecounty/taxonomy/term/4/9" title="Administrative department" class="actuator" id="actuator2">administration (12)</a></li>
<ul class="submenu" id="menu_2">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_2', 'actuator2'));
  } 
</script>
<li><a href="/alpinecounty/departments/administration/employment_forms" title="" class="dhtml_node">Employment Forms</a></li>
<li><a href="/alpinecounty/departments/administration/contact" title="" class="dhtml_node">Contact Administration</a></li>
<li><a href="/alpinecounty/departments/administration/requests_for_proposals_qualifications" title="" class="dhtml_node">Requests for Proposals  &amp; Qualifications</a></li>
<li><a href="/alpinecounty/departments/administration" title="" class="dhtml_node">Administration</a></li>
<li><a href="/alpinecounty/images/vote" title="" class="dhtml_node">Vote</a></li>
<li><a href="/alpinecounty/images/leash_law" title="" class="dhtml_node">Leash law</a></li>
<li><a href="/alpinecounty/images/winter_drive" title="" class="dhtml_node">winter drive</a></li>
<li><a href="/alpinecounty/images/weeds" title="" class="dhtml_node">Weeds</a></li>
<li><a href="/alpinecounty/images/drupal_small" title="" class="dhtml_node">drupal_small</a></li>
<li><a href="/alpinecounty/images/drupal" title="" class="dhtml_node">drupal</a></li>
<li class="menubar"><a href="/alpinecounty/taxonomy/term/76/9" title="Jobs, RFPs, RFQs" class="actuator" id="actuator3">human resources (2)</a></li>
<ul class="submenu" id="menu_3">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_3', 'actuator3'));
  } 
</script>
<li class="menubar"><a href="/alpinecounty/taxonomy/term/81/9" title="View open job positions with Alpine County." class="actuator" id="actuator4">employment (1)</a></li>
<ul class="submenu" id="menu_4">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_4', 'actuator4'));
  } 
</script>
<li><a href="/alpinecounty/departments/administration/human_resources/employment/employment_opportunities" title="" class="dhtml_node">Employment Opportunities</a></li>
</ul>
<li class="menubar"><a href="/alpinecounty/taxonomy/term/84/9" title="" class="actuator" id="actuator5">safety (1)</a></li>
<ul class="submenu" id="menu_5">

<script language="JavaScript" type="text/javascript"> 
  if (isJsEnabled()) { 
    addLoadEvent(initializeMenu('menu_5', 'actuator5'));
  } 
</script>