Image Library is not saving image

[eluser]Patrick Reck[/eluser]
I am trying to fetch a picture of a bear from the URL and save it as aabear.jpg. However, my code is failing. What is wrong?

Code:

$config['image_library'] = 'gd2';
$config['source_image'] = 'http://thejuxtapositionape.blog.com/files/2012/03/polar-bear-pup.jpg';
$config['create_thumb'] = TRUE;
$config['maintain_ratio'] = TRUE;
$config['width']  = 75;
$config['height'] = 50;
$config['new_image'] = 'aabear.jpg';

$this->load->library('image_lib', $config);