Enabling Anti Splog Additional protection also for users signups.

I'm using the Anti-Splog plugin. It's workig fine to stop spam blogs creation. But I have hundreds of users signing up daily (without creating a blog). I would like to enable the Additional Signup Protection (capchta or admin questions) also for users signing without requiring a blog to be created. Actually the Additional Signup Protection is only present if a user asks also for a blog. I cannot find a way to enable it for both. How can I solve? Thanks!!!