Using catch_the_image to get the thumbnail size

You can add your own named image size by adding code to your functions.php.

Something in the line of
add_theme_support(‘post-thumbnails’);//might not be necessary
add_image_size(‘front-end-150’, 300, 300);

Now you should be able to use in your catch_that_image()

wp_get_attachment_image($post->ID, 'front-end-150')

for all newly uploaded images.

Your past images don’t have the front-end-150, so you might want to use the regenerate thumbnail plugin (http://wordpress.org/extend/plugins/regenerate-thumbnails/)

Good luck!