Large image size stuck on old value, even for new images

Find the actual large version of the image file (i.e., wp-content/uploads/2014/03/my-image-1024×576.jpg) and see if in fact it has the smaller dimensions or if it is just being rendered that way in your theme. If the large version is in fact 1024px wide, then the filter is working.

Make sure you are referencing the right image size in the theme:

<?php echo get_the_post_thumbnail($post->ID, 'top-stories-home'); ?>

Also, makes sure that your CSS is not manually reducing the size of the image. If the image is being used as a DIV background and the CSS is reducing the size of the DIV, the image will also be smaller.

For example:

.div {
    max-width: 586px;
    max-height: 500px;
}

If the actual values in the drop down boxes are incorrect, clear cache if you use caching plugins.