BuddyPress.org

Wow! You could install BP in Yahoo! Hosting? I’ve seen many support questions at WordPress.org/forums where users are bogged down or get errors with that hosting, didn’t know that Yahoo! had mod_rewrite enabled

You can login on the sidebar at http://3rut.com/3rut/ where your BP is installed. Not sure if this is going to work with Yahoo! hosting, but test if this could be added to your wp-config.php

Allow BuddyPress to function on multiple blogs of a WPMU installation, not just on one root blog:

define ( 'BP_ENABLE_MULTIBLOG', true );