I’m pretty sure the WordPress cropping feature requires the php-gd library to be installed on the server. I had the same problem locally, but after installing the php-gd library the problem disappeared.
Please note: This will not crop images that were uploaded before php-gd was installed. You will need to either manually upload the images again, or use the Regenerate Thumbnails plugin.
What version of WP are you using rpophessagr? I found that anything within 3.0+ doesn’t crop using the add_image_size( 'featured', 200, 225, true ); statement. It’s almost as if it is being called to late??
Instead you can head to the Settings>Media area and adjust the thumbnail dimensions within there. Then upload an image to your post and you will see your specified dimension on the ‘thumbnail’ radio button.
Good luck. I wish someone had posted this when I was trying to work it out. But now I am attempting to help others. Hope this works for you.
Even relying only on Settings > Media I can’t obtain what I want (images cropped to a fixed dimension). I’ve been stuck for two days and I’m starting to suspect the existence of a bug.