[thelist] <optgroup> bug?

[Jason Morehead]

hey all...

i've been using the <optgroup> tag one on my sites, and i've noticed something odd.  every so often, the hierarchical menus will shift.  for example, the submenu for topic A will apper on topic B, the submenu for topic C will appear on topic B, and so on.  however, if i look at the html code, everything is correct.  has anyone else run into this problem?  admittedly, i've only seen this in IE5.x for the mac, so maybe this is a browser bug.  if you want to see the site in questions, it's at http://www.opuszine.com/.  much thanks...

jason