The captcha check always seems to fail when trying to sign up. Also see this IRC log:

[16:48] you should allow anonymous user to post comments..
[16:48] ps. comments are not vissible due to a regression in latest yellowgrass: https://yellowgrass.org/issue/YellowGrass/323
[16:53] Arik: We probably won´t because of spam but we also like to find users of the tools
[16:54] chrismelman1: maybe, but this registration process doesn’t work for me - the question of ‘Arik you human’ keeps giving me strings to copy, for about 5 times I tried to register..
[16:54] ‘Are you human’

Submitted by Lennart Kats on 20 January 2013 at 11:15

I can confirm that I was unable to register sign up for an account with the same email address as my current account. The sign up form would ask another captcha every time the register button was pushed.

*bump*

This still appears to happen! The captcha is easy but it never works.