Editing Theme Functions Doesn't Affect Site

I recently attempted to create a new wordpress site to showcase an Architectural Portfolio. I was using the Architekt Theme, but have run into some problems. Although I have gotten it to work as it should be used I am unable to resize the portfolio images. I edited part of functions.php to read:

if ( function_exists( 'add_theme_support' ) ) { // Added in 2.9
  add_theme_support( 'post-thumbnails' );
  add_image_size('featured-slideshow',959,349,true);
  add_image_size('featured-big',369,408,true);
  add_image_size('featured-medium',369,196,true);
  add_image_size('featured-small',60,58,true);
  add_image_size('featured-blog',306,215,true);
  add_image_size('featured-portfolio',369,400,true);
  add_image_size('featured-side',306,215,true);
  add_image_size('featured-blog-listing',625,152,true);
  add_image_size('featured-port-listing',400,400,true);

I changed the portfolio featured-port-lsting and featured-portfolio, but nothing has changed.