userGroups::captcha not showing in register page

Hi, All

new to yii and recently playing around with extension userGroups which is pretty cool,

except i found

<?php $this->widget(‘CCaptcha’); ?> not showing the image under /userGroups/user/register page

it works under site/contact page and anywhere else though

thought i might do something wrong, i create a brand new yii webapp and install usergroups

yii 1.1.8 under window xampplite 1.7.3