Captcha causing timeout after upgrade to 3.0.3

After I upgraded to 3.0.3, my project is causing Fatal errors, it times out after 30 seconds with this message:

Code:

Fatal error: Maximum execution time of 30 seconds exceeded in /home/milos/ci3_system/helpers/captcha_helper.php on line 174

When I replace the system/helpers/captcha_helper.php with that from 3.0.2, everything works fine, also when I access pages which don't generate captcha everything works just fine.

I'm using PHP 5.6.9 on Debian (32bit) 8.1. Here's the output of phpinfo() - http://numberstation.cf/html/phpinfo.htm
This is from my local development server, I'm just posting saved HTML page on my site (btw, what's the easiest way to post phpinfo() output online?).

This is the code I'm using to generate Captchas:

In MY_Controller

PHP Code:

protected function createCatcha(){
        $values = $this->_data['captcha_params'];

        return create_captcha($values);
    } 


Captcha parameters array comes from a config file:

PHP Code:

$config['captcha_params'] = array(
        'word_length' => 4,
        'img_path' => './captcha/',
        'img_url' => base_url('captcha/'),
        'font_path' => ('./fonts/OpenSans-Light.ttf'),
        'font_size' => 20,
        'img_height' => 40,
        'img_width' => 180,
        'pool' => '123456789ABCDEFGHKLMNPRSTUVWXYZabcdefghijkmnpqrstuvwyz',

        'colors' => array(
            'background' => array(240,240,240),
            'border' => array(120,120,120),
            'text' => array(20,0,0),
            'grid' => array(120,120,120)
            )
        ); 


Then in controller methods where I need Captcha I do this:

PHP Code:

$this->_data['captcha'] = $this->createCatcha(); 


and pass it to views.

Is this some problem with my server setup and how can I fix it?

Duplicate: http://forum.codeigniter.com/thread-63481.html