mike,
it´s been possible with encore, but you need to do some more work on your multi-page-menu.
you need to "slice" all your elements, to take care about your buttons and as stan has posted - buttons could not overlap as well within BD as within DVD.
you need to take care to get back to the previous menu - mostly with the same buttons at the same places as your previous page.
please look here:
http://rivergatesoftware.com/tutorial-12tangos
cheers
danny