Suckerfish vertical dropdown won't work Win/IE6

Drupal 5.1
php4

a simple phptemplate, all-css theme

i've installed the Suckerfish javascript to page.tpl.php

<script type="text/javascript"><!--//--><![CDATA[//><!--

sfHover = function() {
  var sfEls = document.getElementById("nav").getElementsByTagName("LI");
  for (var i=0; i<sfEls.length; i++) {
    sfEls[i].onmouseover=function() {
      this.className+=" sfhover";
    }
    sfEls[i].onmouseout=function() {
      this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
    }
  }
}
if (window.attachEvent) window.attachEvent("onload", sfHover);

//--><!]]></script>

i've placed the dropdown menus in a block; easier to style that way.

i know the stylesheet is working because even on Win/IE6, the menus change color on hover (that'd be the )

the dropdown (fly-out, i guess, since this is a vertical menu) works on Firefox, Mac, etc

any reason why this would not be working? it seems other people have had no trouble getting Suckerfish working with Drupal.

my install is a multi-site, one Drupal install; that is, the files are at /sites/linn.testbcd.org/themes/ -- might that make any difference?

i added the javascript to a Bluemarine theme and it did not work either, so it's not my theme.

http://linn.testbcd.org

thanks!