Anti-Splog: Users can't register public blogs

With the Anti-Splog plug-in activated, users are unable to register new blogs. Registration is working fine, but once registered - and I've been able to verify this - they can't create new blogs marked public.

Disabling Anti-Splog works fine. (I deactivated Anti-Splog and reactivated BP-Humanity, the other plugin I've been testing for this purpose.)

What typically can cause that error? How can you control what Roles / at what time users can register blogs, generally? (obviously, being able to block blog creation on initial signup can be another way to discourage splogs, if we did have more control)

This is BP 1.2.6.