undefined image_style_url() in template.php

Hey there, I upgraded and got this fatal error:

Fatal error: Call to undefined function image_style_url() in /var/www/example.com/sites/all/themes/granada/template.php on line 9

Thanks in advance for checking it out!

Drush update printout:

 Name           Installed  Proposed    Status                                                                                
 Drupal core    6.20       6.20        Up to date                                                                       
 Chaos tool suite     6.x-1.8    6.x-1.8     Up to date                               
 DesignKit      6.x-1.0-beta1  6.x-1.0-beta1  Up to date                               
 Dialog API     6.x-1.0-alpha1  6.x-1.0-alpha1  Up to date                               
 ImageAPI       6.x-1.9    6.x-1.9     Up to date                               
 ImageCache     6.x-2.0-beta10  6.x-2.0-beta10  Up to date                               
 ImageField     6.x-3.9    6.x-3.9     Up to date                               
 jQuery UI      6.x-1.4    6.x-1.4     Up to date                               
 jQuery Update  6.x-2.0-alpha1  6.x-2.0-alpha1  Up to date                               
 Skinr          6.x-2.x-dev  6.x-2.x-dev  Up to date                               
 Granada        6.x-1.x-dev  6.x-1.x-dev  Up to date                               
 Fusion         6.x-1.0    6.x-1.0     Up to date