Characters problem when including an external PHP code

[Triky]

I have this plugin:

PHP Code:

ob_start();
  include('includes/klayz_latestposts.php');
  $latest_post_klayz = ob_get_contents();
  ob_end_clean(); 


klayz_latestposts.php:

PHP Code:

<?php
require('../wp-blog-header.php');
?>

<?php query_posts('showposts=10'); ?>
<?php while (have_posts()) : the_post(); ?>
<a href="<?php the_permalink() ?>" rel="bookmark" title="Link per <?php the_title(); ?>"><?php the_title(); ?></a><br />
<?php endwhile;?>

But.. activating the plugin I get these characters errors:

http://i49.tinypic.com/2wh01h0.jpg

Why?
Can you please help me?