The solution <?php query_posts('posts_per_page=9'); ?> to limit author related posts show the entire website post :(

  <?php
    $curauth = (isset($_GET['author_name'])) ? get_user_by('slug', $author_name) : get_userdata(intval($author));
  ?>
  <h2>About: <?php echo $curauth->nickname; ?></h2>
  <dl>
    <dt>Website</dt>
    <dd><a href="<?php echo $curauth->user_url; ?>"><?php echo $curauth->user_url; ?></a></dd>
    <dt>Profile</dt>
    <dd>
      <?php echo $curauth->user_description; ?>
    </dd>
  </dl>

  <h2>Posts by <?php echo $curauth->nickname; ?>:</h2>

  <ul>
    <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
      <li>
        <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link: <?php the_title(); ?>">
          <?php the_title(); ?>
        </a>,
        <?php the_time('d M Y'); ?> in
          <?php the_category('&');?>
      </li>

      <?php endwhile; else: ?>
        <p>
          <?php _e('No posts by this author.'); ?>
        </p>    
      <?php endif; ?>
  </ul>