query_posts stopped work after 3.1 upgrade

Hi,

maybe I am not alone. After upgrade to WP 3.1 my custom queries stopped work. Example:

[please mark your code using backticks or the code button]

$args = array(
    'post_type' => 'post',
    'category_name' => 'novinky',
);

query_posts($args);

while( have_posts() ) : the_post();
...
endwhile;

Do I anything bad? Is there any fix? My all website is now empty, I am loosing visitors.