Can’t use two loops on one page

<?php $my_query = new WP_Query('category_ID=3&amp;showposts=2'); ?>

<?php while ($my_query->have_posts()) : $my_query->the_post(); $do_not_duplicate = $post->ID; ?>

<?php endwhile; ?>

Divs divs.

<?php $my_query = new WP_Query('category_ID=1&amp;showposts=1'); ?>

	<div class="posts"><?php if(have_posts()) : ?><?php while ($my_query->have_posts()) : $my_query->the_post(); ?>

Content content

	<?php endwhile; ?>

<div class='navigation'>
<?php posts_nav_link(); ?>
</div>

	<?php endif; ?>

Only the second group of posts (category 1, which is Uncategorized) is displaying on the page.