Im using Anti-Splog (latest version) with WP 3.5. I have set it NOT to spam blogs on signup (see screenshot 1).
However blogs are occasionally being incorrectly spammed upon signup (see screenshot 2). Although the blog shown has a path that looks to be spam, in this case having spoken to the user I am certain that it is not.
The splog certainty is marked as 0% so it should never have been spammed based on that figure. Also the method is marked as 'manual' even though the blog was spammed automatically, just compare the 'registered' and 'spammed' times.
Is it possible to look back at the logs at your end and look into this further? Please let me know if you need anymore info.