Hi!
I had the same problem and I just created a test environment, fresh installation of WordPress, then I enabled BuddyPress and then only the plugin “BP Registration Options”.
I created a test user and activated the account. Then I logged in on the site, without “Approve” the user, and I was able to post a activity on the “What’s new, [user_name]?” field.
The user should not be able to interact before his approval, so this looks like more a bug in the plugin, unfortunately…
