WordPress - Get posts in custom taxonomy category
===

I have a bit of a strange problem with my WP-query. I have a custom post type (portfolio), with a custom taxonomy called year. I have categories for each year, so what I want to do is display all posts for each year. The problem is, only 2012 works. Doesn't matter if I order the categories ASC/DESC - only 2012 works.

    <section id="content">
    	<?php
    	$categories = get_categories('taxonomy=year&order=DESC');
    	foreach($categories as $category) : ?>
    	<article class="year">
    		<h2><?php echo $category->name ?></h2>
    		<div class="items">	
    		<?php
    		$posts = get_posts('taxonomy=year&post_type=portfolio&year=' . $category->slug);
    		foreach($posts as $post) : ?>
    			<div class="item">
    			<?php 
    			$large_image_url = wp_get_attachment_image_src( get_post_thumbnail_id(), 'full');
    			echo '<a href="' . $large_image_url[0] . '" title="' . the_title_attribute('echo=0') . '" rel="lightbox[' . $category->slug . ']" >';
    			the_post_thumbnail('thumbnail');
    			echo '</a>';
    			?>
    			</div>
    		<?php endforeach; ?>					
    		</div>	
    	</article>
    	<?php 
    	endforeach;
    	wp_reset_query();
    	?>
    </section>

What am I doing wrong? To me, it seems right.. I've tried a bunch of different takes on this, everything from real querys to ridiculous sortings but I just can't get it right..

Thank you in advance!