Header Image Disappeared

Hello all,

I had a problem in my blog: posts show the picture that was inside the post (featured picture) – i tired to remove it in the regular way through “edit” in the post. though, every time the picture kept shown on the header.
so i tried to remove it from the header.php code and now i dont have image header at all in the main page.

this is the code i have inside the header.php:
// Check if this is a post or page, if it has a thumbnail, and if it’s a big one
if ( is_singular() && current_theme_supports( ‘post-thumbnails’ ) &&
has_post_thumbnail( $post->ID ) &&
( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), ‘post-thumbnail’ ) ) &&
$image[1] >= HEADER_IMAGE_WIDTH ) :
// Houston, we have a new header image!
//echo get_the_post_thumbnail( $post->ID );

i will be happy to hear any suggested solution.
thanks.

by the way i have twenty ten with child theme.