Das habe ich auch schon versucht, nur weiß ich leider nicht wo. Durch meine anderen Recherchen habe ich das Gefühl, das mir ein div-Tag fehlt... Eine category.php habe ich übrigens nicht. Hier mal meine komplette index.php:
[FONT=Courier New][size=8]<?php get_header(); ?>
<?php if (have_posts()) : ?>
<?php $post = $posts[0]; // Thanks Kubrick for this code ?>
<?php if (is_category()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Archive for'); ?> <?php echo single_cat_title(); ?></h2>
</div>
<?php } elseif (is_day()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Archive for'); ?> <?php the_time('F j, Y'); ?></h2>
</div>
<?php } elseif (is_month()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Archive for'); ?> <?php the_time('F, Y'); ?></h2>
</div>
<?php } elseif (is_year()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Archive for'); ?> <?php the_time('Y'); ?></h2>
</div>
<?php } elseif (is_author()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Author Archive'); ?></h2>
</div>
<?php } elseif (is_search()) { ?>
<div class="page-title">
<h2 class="page-title-border"><?php _e('Search Results'); ?></h2>
</div>
<?php } ?>
<?php while (have_posts()) : the_post(); ?>
<div class="post" id="post-<?php the_ID(); ?>">
<div class="title">
<h2 class="posttitle">
<a href="<?php the_permalink() ?>" rel="bookmark" title="<?php _e('Permalink to'); ?> <?php the_title(); ?>"><?php the_title(); ?></a>
</h2>
<p class="postmeta">Posted under <?php the_category(', ') ?> | <?php comments_popup_link(__('No Comment'), __('1 Comment'), __('% Comments'), 'commentslink', __('Comments are off')); ?> <?php edit_post_link(__('Edit'), ' · ', ''); ?>
</p>
</div>
<div class="postentry">
<?php if (is_search()) { ?>
<?php the_excerpt() ?>
<?php } else { ?>
<?php the_content(__('Read the rest of this entry »')); ?><div style="clear:both;"></div>
<?php } ?>
</div>
<!--
<?php trackback_rdf(); ?>
-->
</div>
<?php endwhile; ?>
<div class="pages">
<div class="pages-border"></div>
<span class="page-previous"><?php posts_nav_link(' ', '', __('« Older Entries')); ?></span>
<span class="page-next"><?php posts_nav_link('', __('Newer Entries »'), ''); ?></span>
</div>
<?php else : ?>
<div class="post">
<h2><?php _e('Error 404 - Not found'); ?></h2>
</div>
<?php endif; ?>
<?php get_sidebar(); ?>
<?php get_footer(); ?>[/SIZE][/FONT]