This plugin is great and I wish it can be one of those to be core plugins in next versions of WordPress!
Just one thing I guess it ould be better is to fix the implementation inside the menus system admin UI in WP3.1.1. The title of posts that are multilanguage appear like this <!--:pt-->Casa<!--:--><!--:en-->Home<!--:--> instead of being translated as well.
Expected to translate with the current language. Is there any filter / hook to fix this problem inside the menu system UI? If not, try to ask for the wrdpress core developers... they should open a filter for you ;)