is_archive() content being shown instead of is_category()

My Issue:

If I browse to http://mysite/category/mycategory, the if (is_category()) content isn’t displayed, the if(is_archive()) is shown instead.

My code:

archive.php:

<?php include('includes/resultlist.php')?>

search.php:

<?php include('includes/resultlist.php')?>

includes/resultlist.php:

<?php get_header(); ?>

            <div class="main">

<?php if (is_archive()) { ?>

            <h1>Artigos publicados em <?php single_month_title(' '); ?></h1>

<?php } else if (is_search()) { ?>

            <h1>Resultados para "<?php the_search_query(); ?>"</h1>

<?php } else if (is_category()) { ?>

            <h1>Resultados para categoria "<?php the_category(); ?>"</h1>

<?php }

if ( have_posts() ) while (have_posts()) { the_post(); ?>

                <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
                por <span class="date"><?php the_author(); ?></span> em 
                <span class="date"><?php the_date(); ?></span>

                <p><?php echo get_the_excerpt(); ?> <a href="<?php the_permalink(); ?>">Leia mais</a></p>

             <?php } 

else {?> 

            <h2>Nada encontrado</h2>
            <p>Desculpe, não encontramos o que você procurava!</p>

<?php }

include('pagination.php');

?>

            </div><!-- /main -->

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

What I tried:

Created a category.php file with the contents: <?php include('includes/resultlist.php')?> but the issue persits. I included some garbage text on the end of category.php and it shows on the end of the rendered page, so the file is being called, I suppose.

My environment:

LAMP Ubuntu 64 bit with apache, mysql and php installed with default options via apt-get.