In the page.tpl.php, there is some code that checks if the page is the front page of a site. If so, it wraps the site-title in an H1 tag. Later in the template, the page title is also wrapped in an H1 tag. Per the w3c spec, each page should only have 1 H1 tag. Also, for semantic and seo reasons, that H1 tag should never ever be the site title, it should always be the title of the page -- and different for each page. Otherwise, you will garner very bad search engine placement. The H1 tags being unique is crucial. Many Drupal themes make this mistake.
This is the offending code:
<?php if ($site_name): ?> <?php // Use an H1 only on the homepage $tag = $is_front ? 'h1' : 'div'; ?> <<?php print $tag; ?> id='site-name'><strong> <a href="<?php print $base_path; ?>" title="<?php print t('Home'); ?>" rel="home"> <?php print $site_name; ?> </a> </strong></<?php print $tag; ?>> <?php endif; ?>
<?php if ($site_name): ?> <div id='site-name'> <a href="<?php print $base_path; ?>" title="<?php print t('Home'); ?>" rel="home"> <?php print $site_name; ?> </a> </div> <?php endif; ?>
I also removed the strong tags since they can be accomplished with css and are unnecessary. This might seem trivial, but it's huge for SEO, semantics and accessibility. Many references on google search about this.