Query posts by category OR page

hi there,

i have a website using wordpress. on the front page i have a banner slideshow of the small screenshots from the portfolio category (in my case, cat=9). the banner is from the custom field of each portfolio posts and have links to the specific post.

here is the code:

<?php query_posts('cat=9');
	$slide = 1;
	while (have_posts()) : the_post();
	if (post_custom('preview')) { ?>
	<div id="slideshow<?php echo $slide;?>"<?php if ($slide != 1) { ?> style="display: none;"<?php } ?>>
	<a href="<?php the_permalink();?>">
	<img src="<?php echo post_custom('preview');?>" alt="<?php the_title();?>" class="previewpic" />
	<span><?php the_title();?></span>
	</a>
	</div>
	<?php $slide++;} endwhile; ?>

what i want to do now is add the query post so that the banner will shows not only from cat=9 but also from page_id=2 (this is the about us page).

i try to put like this:

<?php query_posts('cat=9&page_id=2');

..and so on..

but it doesn’t work, only shows the banner from the page_id=2.

I would be tremendously obliged if you help me and tell me how to get this done.

thanks.