Odd. I have updated several sites that do not have the BP plugin and they do not show that message. Only the http://www.eastsideclassiccarclub.com web site shows it. It is my only BP site. Set up as a test platform for other sites I will be creating in the near future.
I too have this issue. But I see some members in my users list but they do not show up on the members plugin list. So no one can see that they even exist in the group. Is there a way to force activate or log in for them?