How to show different CAPTCHA on every new attempt in Yii::CCaptcha

To show CAPTCHA after N unsuccessful attempts read this:
http://www.yiiframework.com/wiki/339/show-captcha-after-n-unsuccessfull-attempts

Simple CAPTCHA implementation in Russian:
http://yiiframework.ru/doc/cookbook/ru/form.captcha
Hope they will translate it soon to english

If you want to show different CAPTCHA on every user's new attempt to post/login/etc.. simply add
'testLimit'=>'1', in actions();


public function actions(){
return array(
   'captcha'=>array(
'class'=>'CCaptchaAction',
'testLimit'=>'1',
   ),
);
   }