Also glad to help.
On one of the boards I used to run we had a similar problem with opening registration. We added one question to the form, something beyond simple, I believe the question even had the answer, and had it be an open ended field. EVERY bot filled that field with either a "city name", "yes", or "no".
For example "Where is the University of Massachusetts flagship located (city)?"
The moderators of the board could quickly delete bot-users and promote the real people with a quick look. We also allowed new users one post before being moderated, this allowed for a quick one off response, but not too much potential for SPAM. (I don't think that would be wise here.)
Questions, comments, etc about UMassHoops.com.