SZ4H on "Problem with using paging for custom post type"

Hello
I have a problem showing my category page in pageing
I have a custom post type named 'videos'
I put all the posts of this type in a one category names 'cars video'
I use a template page category-9.php' as the id of this category 'cars video' is '9'

I place this code at the top of my loop

<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
?>
		<?php query_posts( $query_string . '&post_type=videos&posts_per_page=10&paged=' . $paged ); ?>
		<?php if ( have_posts() ) : ?>
			<?php
			/* Start the Loop */
			while ( have_posts() ) : the_post();
etc.......

I got the first page 'sitename.com/blog/category/cat-videos/' working fine but I have this pages not working
'sitename.com/blog/category/cat-videos/page/1'
'sitename.com/blog/category/cat-videos/page/2'
etc..

it gave me 404.php page

Any advices?