The menu has nothing but floated elements in it, so the actual height of the top level element rendered by the menu when using CSS adapters is 0! This means that you can't have an enclosing element to span the whole width because it will not adjust to the height of the menu (in horizontal orientation). I just thought you should know, because that really makes it touch to create something like this:
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Menu Menu Menu
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It will not fill the space up that the menu occupies, so you can't have background extend to the right. Hope you understand what I mean. You would say: why not specify height for the enclosing element? Because it must eb the exact same height of the elements within. And these have an extra style height: 1% to work around a bug in IE, so it's a no go. Can't have the same height as the menu.
Too bad this project is utterly dead, I guess it was too much to ask from the community. I think Microsoft should pay the main developer to release an update.