Avoid duplicated posts

Hi,

I followed this instructions and I could avoid the duplicate posts, but the matter is that I only display 3 posts on the differents colums… You’ll see “Secundaria” in blank.

How can I put posts_per_page=3 to show the last 3 post, but not duplicated, the previous ones, do you understand?

I hope you can help me.

Link: http://bit.ly/VAlj66

A fragment of my code:

<ul>
				<!-- NOVEDADES SECUNDARIA -->
				<?php query_posts('cat=1,-3,-4,-102,-100,-111&order=DESC&posts_per_page=3'); if ( have_posts() ) : while ( have_posts() ) : the_post();  if (!in_array($post->ID, $ids)) { ?>
				<li id="gradeNews-<?php the_ID(); ?>">
					<div class="postImage">
						<a href="<?php the_permalink(); ?>"><?php echo get_post_image('thumbnail','','default-thumb'); ?></a>
					</div>
					<div class="postInfo">
						<div class="postTitle">
							<h4><a href="<?php the_permalink(); ?>" title="Link permanente a <?php the_title_attribute(); ?>"><?php short_title('','…',true, '35'); ?></a></h4>
							<p class="postMeta"><?php the_time('j F, Y'); ?></p>
						</div>
					</div>
				</li>
				<?php } endwhile; else: ?>
				<li><em>No hay noticias en Secundaria!</em></li>
				<?php endif; ?>
				<?php wp_reset_query();?>
			</ul>

Thanks you!