After upgrading to vBulletin 3.7.1 almost within 15 minutes I had 3 new sign-ups, all from .cn21.com names. So I could tell they were going to be spammers, so I banned them and their ip addresses.
I thought that would be the end of it. Well almost an 1 hour later I got 6 more sign-ups, I thought WTF! How are they getting by the Recaptcha? I went into my AdminCP and double checked everything and it looked alright.
So I headed over to vBulletin support forums and found out that I am not the only who has had problems. So I felt a little better that I wasn’t the only experiencing the problem. So reading over there I found a new modification that people were recommending, so that is what I am using and since I installed it, not one spambot.
For the past year or so I have be using the NoSpam! modification and hardly had any spammers at all. Unfortunately no one has ported it over to 3.7 yet. So hopefully everything will get fixed in the next patch or better yet, I might just stick with the new modification.