Thank you for this great, useful plugin. It seems like a real smart blocking process.
I have installed ce plugin and asked to receive the detected spams by mail just to check if it worked ok for me.
But I received a few "real" comments from "real" users which had been blocked (in addition to many spams, of course !).
These "real" comments always had the error described as follows :
Error: empty answer. 
How can I fix that ? I can't use the plugin if it blocks real users now and again.