ich habe Dir den Code mal angepasst, womit Du das testen kannst, ich selber habe es allerdings nicht getestet, d.h. ohne Gewähr 
PHP
<?php
/**
* @package Coraline
* @since Coraline 1.0
*/
?><!DOCTYPE html>
<!--[if IE 6]>
<html id="ie6" <?php language_attributes(); ?>>
<![endif]-->
<!--[if IE 8]>
<html id="ie8" <?php language_attributes(); ?>>
<![endif]-->
<!--[if (!IE)]><!-->
<html <?php language_attributes(); ?>>
<!--<![endif]-->
<head>
<meta charset="<?php bloginfo( 'charset' ); ?>" />
<title><?php wp_title( '|', true, 'right' ); ?></title>
<link rel="profile" href="http://gmpg.org/xfn/11" />
<link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>" />
<?php wp_head(); ?>
</head>
<body <?php body_class(); ?>>
<div id="container" class="hfeed contain">
<?php do_action( 'before' ); ?>
<div id="header">
<div id="masthead" role="banner">
<?php $heading_tag = ( is_home() || is_front_page() ) ? 'h1' : 'div'; ?>
<<?php echo $heading_tag; ?> id="site-title">
<span>
<a href="<?php echo home_url( '/' ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a>
</span>
</<?php echo $heading_tag; ?>>
<div id="site-description"><?php bloginfo( 'description' ); ?></div>
</div><!-- #masthead -->
<div id="access" role="navigation">
<?php /* Allow screen readers / text browsers to skip the navigation menu and get right to the good stuff */ ?>
<div class="skip-link screen-reader-text"><a href="#content" title="<?php esc_attr_e( 'Skip to content', 'coraline' ); ?>"><?php _e( 'Skip to content', 'coraline' ); ?></a></div>
<?php /* Our navigation menu. If one isn't filled out, wp_nav_menu falls back to wp_page_menu. The menu assiged to the primary position is the one used. If none is assigned, the menu with the lowest ID is used. */ ?>
<?php wp_nav_menu( array( 'container_class' => 'menu-header', 'theme_location' => 'primary' ) ); ?>
</div><!-- #access -->
<div id="branding">
<?php
// Check to see if the header image has been removed
if ( '' != get_header_image() ) :
?>
<a href="<?php echo home_url( '/' ); ?>">
<?php
/*
// The header image
// Check if this is a post or page, if it has a thumbnail, and if it's a big one
if ( is_singular() && has_post_thumbnail() && ( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id(), 'post-thumbnail' ) ) && $image[1] >= HEADER_IMAGE_WIDTH ) :
// Houston, we have a new header image!
the_post_thumbnail();
else :
*/
?>
<img src="<?php header_image(); ?>" width="<?php echo get_custom_header()->width; ?>" height="<?php echo get_custom_header()->height; ?>" alt="" />
<?php //endif; // end check for featured image or standard header ?>
</a>
<?php endif; // end check for removed header image ?>
</div><!-- #branding -->
</div><!-- #header -->
<div id="content-box">
