Now I have tested it on a completely new setup but I still get the same problems. Although in FF i dont get any error message.
But the expanding menu is still not opening a url if clicked. When going through your example it strikes me that you dont have any such example yourself. So maybe I ask the wrong question.
This is what I am after:
This of a meny like this:
If clicking on Start you end up on /start.html
Clicking on Animals, you end up on /animals.html but with that bransch expanded. So you actually not expand the bransch onclick since there is no time before the page reloads.
See what I mean?