Infinite loop using CAPTCHA captcha helper.php. CodeIgniter 3.03

I also found an infinite loop using CAPTCHA on CI 3.03.

But only happens when the word ('word'=> '') is not provided.

If I provide the word CAPTCHA library works fine. With out it the infinite loop comes back again.

So I end up doing this to solve the problem: word=>random_string('alnum', 8);