Users Not Being Added to Main Site

I am running WP 3.2.1 with BP 1.2.9 and a lot of plugins (mostly from WPMU Dev).

It looks like the users that choose to create a blog during registration are not being added to the main site, only to the blog they create. Is that possible? Still researching and trying to figure out why I have so many users *not* on the main site.

I'm hoping there is just some setting somewhere that I forgot to tick.

I am using New Blog Templates to create the new blogs.

Any ideas?