Users can't activate account

I’ve set up the WordPress with latest BuddyPress (and bbPress) for a closed group of people. As they wanted it to be private I’ve installed your plugin but now new users can’t activate their accounts (I have invitation code set up to keep away unwanted users).

When they register they get an e-mail with activation URL but when they click on it they are taken to Login page instead and won’t let them activate it! As if the activation page is blocked unless you’re logged in. Activation works if I uncheck Private site box.

I even tried plug-in ‘BP Auto Login on Activation’ to try to bypass this problem but still wouldn’t work. Can you please help? Thank you.

http://wordpress.org/plugins/jonradio-private-site/