Generally I'm pretty resourceful and can figure these things out, so before I posted here I did confirm that I am using the latest version (I just installed it 2 days ago). Additionally, when I go to the J1.7.0 extension manager no updates are available, and when I go to the CB component, it shows "Your version is : 1.7 & Latest version : 1.7".

I used CB tools to synch users and checked all of the databases, and everything was OK. Then I backed up my database and site files, downloaded the CB 1.7.0 file again and re-installed the CB component. "Public" is still the only group available.