Hi,
You have a suckerfish script running inline near the bottom of your page. I’m not sure if they work down there, it probably needs to be between the HEAD tags but I could be wrong (I don’t know much about javascript). However I always recommend you place the script into an external file and link to it within lt IE6 conditional comments.
You can automate all of this by installing/activating the Multi-level Navigation plugin as it automatically adds the necessary javascripts for you.