Custom main page ruins searchform.php – help?

I am using this on a buddy’s blog to make only posts from specific categories appear in the main field of the blog:

<?php
$page = (get_query_var('paged')) ? get_query_var('paged') : 1;
query_posts("cat=-10,-21,-139,-3&showposts=5&paged=$page");
?>

The other categories appear in the sidebar (not using widgets)

The trouble is when a search is performed, the search results only return the mail page …

Searchform.php:

<form method="get" id="searchForm" action="<?php bloginfo('home'); ?>"/>
	<input type="text" value="<?php echo wp_specialchars($s, 1); ?>" name="s" id="s" /><input id="searchsubmit" type="image" src="<?php bloginfo('template_directory'); ?>/images/btn_search.gif" alt="Submit" />
</form>

Any thoughts?