weird problem about Require Human Verification on Configured Actions

[REZA_JOON]

Hello dear friends
I have this weird problem when in my forum in Admin CP -> User groups -> User-group Manager -> Edit User group (Unregistered) -> Require Human Verification on Configured Actions
set the option to yes and save and it doesn't save to yes and image verification doesn't show in registration i,m sure this problem is not about the server because i have another web site on that server and it works fine

--------------- Added [DATE]1265360356[/DATE] at [TIME]1265360356[/TIME] ---------------

any solution?

[Marco van Herwaarden]

To troubleshoot this, please remove any hacks and disable your plugins, then see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

define('DISABLE_HOOKS', true);

If so, reupload all the original vB non-image files (except install.php). Make sure you upload these in ASCII format and overwrite the ones on the server.

[REZA_JOON]

thanks i don't think this way work

is there any way to enable it through the vb itself???
i mean not admin cp but where the vb files has installed