I've tried almost everything, and WordPress just won't set the post thumbnail size to what I want. It always sets the size to the largest possible, even if I updated the Media settings, and I updated the code in functions.php as well:
if (function_exists('add_theme_support')) add_theme_support('post-thumbnails') set_post_thumbnail_size(150, 90, true) }
Despite the above code, when inserting new thumb/featured image, WP always uses the largest possible size (e.g. 640px width, instead of 150x90).
I'm trying to use it as part of index.php with post excerpts.