[Plugin: BuddyPress Multilingual] WordPress 3.0 and BuddyPress 1.2.5 support

Seems like they have support for it or at least limited support when I read https://wpml.org/2010/06/wpml-1-7-9-wordpress-multisite-and-bug-fixes/ . Never used this plugin though nor has the developer indicated 3.0 support (support til 2.9.2). I guess you could test it in a local server.