Problem mit Posts in Kategorien

<?php get_header() ?>
    <div id="content">
        <?php if(have_posts()): the_post(); ?>
        <div class="post single" id="post-<?php the_ID(); ?>"><div class="post-top">
            <h3 class="title"><?php the_title(); ?></h3>
            <div class="meta icon">
                Geschrieben von <?php the_author() ?> am <?php the_time('j F Y') ?> <a href="<?php the_permalink() ?>#comment"><?php comments_number('Kommentar schreiben','einmal kommentiert','% Kommentare'); ?></a>
            </div>
            <div class="entry">
                <?php the_content('Weiterlesen...'); ?>
            </div>
        </div>
        <div class="post-bottom"></div>
        </div>
        <?php comments_template(); ?>
        <?php else: ?>
            <h2 class="center">Nicht gefunden.</h2>
            <p class="center">Sorry, keine Ergebnisse vorhanden.</p>
        <?php endif ?>


<?php get_sidebar(); get_footer(); ?>

<?php get_header() ?>
                
        <div id="content">
            <?php if (have_posts()) : while (have_posts()) : the_post(); ?>
            <div id="post-<?php the_ID(); ?>" class="post"><div class="post-top">
                <div class="meta">
                    Geschrieben von <?php the_author() ?> am <?php the_time('F-j-Y') ?> <a href="<?php the_permalink() ?>#comment"><?php comments_number('Kommentar schreiben','einmal kommentiert','% Kommentare'); ?></a>
                </div>
                <h3 class="title"><a href="<?php the_permalink() ?>" title="<?php the_title(); ?>"><?php the_title(); ?></a></h3>
                <div class="entry">
                    <?php the_content('Weiterlesen...') ?>
                </div>
            </div>
            <div class="post-bottom"></div>
            </div>
            <?php endwhile; ?>
            <?php if(function_exists('wp_pagenavi')) : wp_pagenavi(); ?>
            <div class="clearleft"></div>
            <?php else : ?>
            <div class="navigation">
                <div class="alignleft"><?php next_posts_link('&laquo; Alte Eintr&aauml;ge') ?></div>
                <div class="alignright"><?php previous_posts_link('Neue Eintr&aauml;ge &raquo;') ?></div>
            </div>
            <?php endif ?>
            <?php else: ?>
            <h2 class="center">Nicht gefunden.</h2>
            <p class="center">Sorry, keine Ergebnisse vorhanden.</p>
            <?php endif ?>
<?php get_sidebar(); get_footer(); ?>

<?php get_header() ?>
 <div id="content">
  <?php if(have_posts()): ?>
  <?php $post = $posts[0]; // Hack. Set $post so that the_date() works. ?>
  <?php /* If this is a category archive */ if (is_category()) { ?>
  <h2 class="pagetitle">Archiv f&uuml;r die Kategorie '<?php single_cat_title(); ?>'</h2>
  <?php /* If this is a tag archive */ } elseif( is_tag() ) { ?>
  <h2 class="pagetitle">Eintr&auml;ge mit den Tags '<?php single_tag_title(); ?>'</h2>
  <?php /* If this is a daily archive */ } elseif (is_day()) { ?>
  <h2 class="pagetitle">Archiv <?php the_time('F jS, Y'); ?></h2>
  <?php /* If this is a monthly archive */ } elseif (is_month()) { ?>
  <h2 class="pagetitle">Archiv <?php the_time('F, Y'); ?></h2>
  <?php /* If this is a yearly archive */ } elseif (is_year()) { ?>
  <h2 class="pagetitle">Archiv <?php the_time('Y'); ?></h2>
  <?php /* If this is an author archive */ } elseif (is_author()) { ?>
  <h2 class="pagetitle">Autor Archiv</h2>
  <?php /* If this is a paged archive */ } elseif (isset($_GET['paged']) && !empty($_GET['paged'])) { ?>
  <h2 class="pagetitle">Blog Archiv</h2>
  <?php } ?>
  <?php while(have_posts()) : the_post(); ?>
  <div class="post single" id="post-<?php the_ID(); ?>"><div class="post-top">
   <h3 class="title"><?php the_title(); ?></h3>
   <div class="meta icon">
    Eingetragen von <?php the_author() ?> am <?php the_time('F j Y') ?> <a href="<?php the_permalink() ?>#comment"><?php comments_number('Kommentar schreiben','einmal kommentiert','% Kommentare'); ?></a>
   </div>
   <div class="entry">
    <?php the_excerpt(); ?>
   </div>
  </div>
  <div class="post-bottom"></div>
  </div>
  <?php endwhile ?>
  <?php if(function_exists('wp_pagenavi')) : wp_pagenavi(); ?>
  <div class="clearleft"></div>
  <?php else : ?>
  <div class="navigation">
   <div class="alignleft"><?php next_posts_link('&laquo; Alte Eintr&auml;ge') ?></div>
   <div class="alignright"><?php previous_posts_link('Neue Eintr&auml;ge &raquo;') ?></div>
  </div>
  <?php endif ?>
  <?php else: ?>
   <h2 class="center">Nicht gefunden.</h2>
   <p class="center">Sorry, keine Ergebnisse vorhanden.</p>
  <?php endif ?>
<?php get_sidebar(); get_footer(); ?>