Bot registration problem

Hi,

I’m having trouble with bots registering on my member site. The site is actually under construction, and I have even password-protected access to the full site. Anyway, in order to register, all the mandatory fields has to be filled out, the new user has to confirm their e-mail address and I have installed the reCaptcha option. Still, I’m getting sign-ups every day from bots, and the bots only have a username and email, so I’m confused how this is possible after doing all measurements of security in order to avoid this. Please help.

The page I need help with: [log in to see the link]