Category.php showing index.php content?

I created a basic custom theme that works great, but the behavior I’m getting from my category.php page is unexpected. If I click any category generated by the wp_list_categories function that has at least one post in it, the category.php page kicks in and displays everything correctly. My problem occurs when I click a category that has no posts in it yet. Instead of getting my category.php page with an erro rmessage and search form, I seem to end up at my index.php instead.

The code in my category.php page is:

<?php get_header(); ?>

	<div id="content" class="narrowcolumn">

	<?php if (have_posts()) : ?>

		<?php while (have_posts()) : the_post(); ?>

			<div class="post" id="post-<?php the_ID(); ?>">
				<h2><a>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></h2>
				<small><?php the_time('F jS, Y') ?> <!-- by <?php the_author() ?> --></small>

				<div class="entry">
					<?php the_content('Read the rest of this entry �'); ?>
				</div>

				<p class="postmetadata"><?php the_tags('Tags: ', ', ', ''); ?> Posted in <?php the_category(', ') ?> | <?php edit_post_link('Edit', '', ' | '); ?>  <?php comments_popup_link('No Comments »', '1 Comment »', '% Comments »'); ?>

			</div>

		<?php endwhile; ?>

		<div class="navigation">
			<div class="alignleft"><?php next_posts_link('� Older Entries') ?></div>
			<div class="alignright"><?php previous_posts_link('Newer Entries �') ?></div>
		</div>

	<?php else : ?>

		<h2 class="center">Not Found</h2>
		<p class="center">Sorry, but you are looking for something that isn't here.

		<?php include (TEMPLATEPATH . "/searchform.php"); ?>

	<?php endif; ?>

	</div>

<?php get_sidebar(); ?>

<?php get_footer(); ?>