Spam registrations worse after adding Captcha

Hi, I’m using this plugin on a site that is not charging, but because of the information provided, wants to control access of many of it’s pages. Therefore, registration is “open” and starts at 0. Recently the client has been complaining of spam registrations, so I added the si-Captcha plugin, per your recommendation. Here’s what I just got from the client:
“the spam situation is actually worse than ever.

From March 18-Apr 14, we had approximately 28 obvious spam registrations.
From April 15-May 12, we had approximately 160. (I lost count a couple of times, the number’s probably higher).”

I’m not sure what to do at this point. The form is very custom and pretty long, so this surprises me. If the link would help, or if there is anything else I can do, please let me know.
Thanks

Hi Becky.

Have you asked the SI-captcha guys about this? Have you also tried other plugins to prevent spam registrations?

What would I be asking them? I used this plugin based on your recommendation. What other plugins do you recommend that we know play well with S2?

You could ask them what could have bypassed their security check and how to improve it, I guess.

I know it’s been recommended because many asked for a captcha solution that is known to not conflict with s2Member, but we don’t keep track of how failproof it is.

I’m not familiar with anti-spam registration plugins, but you can try them and do test registrations to see if any conflict or odd behavior is obvious. http://wordpress.org/extend/plugins/search.php?q=spam+registration