Hi, I’m having the same issue.
I want all the images for related articles to be 220 x 100, so I set this in the functions.php:
set_post_thumbnail_size( 220, 100, true);
That didn’t change anything, not even after forcing regenerating thumbnails.
I also set the theme on ‘non-responsive’ and used http://wordpress.org/plugins/post-thumbnail-editor/
‘Non-responsive’ doesn’t change anything and the post-thumbnail-editor doesn’t either.

Do I need to change something else?
http://www.opbouw.webzy.nl/testomgeving/?p=53