Hello!
It seems that this plugin was last tested with WP 2.9.2 and earlier functionality of BuddyPress. It certainly still works (although I was unable to add images).
But when deleting WP users (normally, spammers managing to register...), it throws the following error:
Call to undefined function remove_user_from_blog()
And the users do not get deleted.
A simple workaround for now is to deactivate the plugin, remove the users normally, and reactivate them again.