Hi Paul, ditto on great plugin and everything.
I'm having problems getting a new user activation achievement to trigger. Other achievements are working.
I'm using a clean wp 3.5.1 install, 2012 theme, with all plugins deactivated except bp 1.7.1 and achievements 3.3
I created a event achievement with
A new user activates their account on your website.
selected from the buddypress group.