Spam users registering to site since update

Since upgrading to WordPress MU 2.9.2 and Buddypress 1.2.2.1, every single day I am getting fake users signing up to my site.

I use WPMU super captcha https://goldsborowebdevelopment.com/product/super-captcha/

WP Spam Free https://www.polepositionmarketing.com/library/wp-spamfree/

Bad Behaviour https://www.bad-behavior.ioerror.us/

WPMU Block Spam by Math https://www.jamespegram.com/wpmu-block-spam-by-math/

All up-to-date.

I am getting slightly annoyed. Before it would be the odd one or two once in a blue moon, but now, every day. What else can I do?