Twenty Ten header.php not closing

I have an issue in IE7 and IE8 where the sidebar is showing text in the h1 size and the page is dropping down by around 500px. My <h1> isnt closing on the home page or the blog. All other pages are taking the entry title from the <div> selection shown below and are working correctly.

What I can’t work out is how to ensure the tag is closed. It works in all other browsers so it’s taken me a while and a html test to find this is where the issue lies.

The header.php code is controlling the <h1> below.

<div id="branding" role="banner">
				<?php $heading_tag = ( is_home() || is_front_page() ) ? 'h1' : 'div'; ?>
				<<?php echo $heading_tag; ?> id="site-title">
					<!--	<span>
					<a>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a>
					</span>

The header is set to a full width customer header too if that helps.

[Please post code or markup snippets between backticks or use the code button.]