theBrettman
Thanks! worked like a charm for me when I added to my funtions.php in my child theme the following
define( ‘HEADER_IMAGE_WIDTH’, apply_filters( ‘twentyeleven_header_image_width’, 1000 ) );
define( ‘HEADER_IMAGE_HEIGHT’, apply_filters( ‘twentyeleven_header_image_height’, 200 ) );
Now my custom image (1000px by 200px) fits perfectly!