Thanks so much for a reply.
I get this message under options with this plugin ( it's not an error message).
"No public, safe sites available.
Note: only public, non-mature and non-dashboard sites appear here. Set the default role for the dashboard site above under Dashboard Settings."
Users were always added to the main blog by default. I still can't add a new user to a sub-site with the same username or email with this plugin. The error is " Sorry that username already exists" even though they are not under users for that site, only on the main one.
How is it possible to have bp users register to other admin sub-sites, much less other bp members sites, when there is a register+ login required because the network is private, and adding a new member won't allow the same username or email to be registered because it recognizes it as registered to the main blog but doesn't honestly already have them on the sub-blog? It's like if buddypress.org was a sub-site of wordpress.org , and there was a registration/login required, I can't have the same identity on both. Seems like even though Bp takes over the network, users are really only on the main site not easily involved in others.
Something like http://wordpress.org/extend/plugins/bp-community-blogs/other_notes/ would be great if it worked or was supported.