Gap left from deleted post when using query posts

Hey all

I am using a query posts call:

<?php
query_posts('showposts=10');
?>
	<?php if (have_posts()) : ?>
	<?php while (have_posts()) : the_post(); ?>
	<?php if (!in_category('8') ): ?>
	<?php if (!in_category('7') ): ?>

to call the last 10 posts from certain categories.

Problem is that I have deleted some posts and it seems to leave a gap in my layout where the deleted post should be instead of showing the next post.

Does anyone know how to work around this and just show the latest posts?

Also is there a function to call 10 posts from several chosen categories and then be able to call 10 posts from other categories below it?

Using the query posts code above only shows 10 posts total on the page instead of each time.

Hope that made sense and someone can help me out.