BuddyPress.org

@Julient

It sounds like a different issue. I assume that you are not getting the WSOD?

If that is the case–that you are not receiving the WSOD–then you should create a new thread as this one is resolved.

I don’t know if it has something to do with the issue, but members who register and don’t create a blog are automatically assigned as subscribers on the root blog. This means that there are hundreds of users assigned to this blog. May this be a problem with buddypress ?

This is normal WPMU behavior. It has nothing to do with BuddyPress.