I have Anti-splog running on my site, but it doesn't seem

Hi

I have Anti-splog running on my site, but it doesn't seem to be stopping a lot. Overnight I had 5 new sites created. Are my settings wrong?

Blog Signup Splog Certainty 80%
Posting Splog Certainty 90%

Spam/Unspam Blog Users - Set to 'no' I don't even understand what this function is supposed to do?

Additional Signup Protection - Recaptcha

Should I change something? Have opened support access for anyone to look if these settings are not enough to go by.

Thanks

Sally