by robert adams » Sun Nov 04, 2007 3:30 am
in order for the captcha to display in the registration page, the correct code for it has to be in the template files of whatever style/template you are using.
many of the older styles, do not have the needed code in the registration file or in the admin panel to be able to turn it on.
the captcha ( correct name is visual confirmation )
was implemented around version 2.0.12 If I remember correctly.
robert