[Plugin: Types – Custom Fields and Custom Post Types Management] Problem with WP_QUERY

I’ve been trying use WP_QUERY to show my posts only if typeofgame is equal to 5×5, however the code below doesn’t show any posts. Typeofgame is a single line of text. If I remove the meta_query bit it shows all posts.

<?
$args = array(

'post_type' => 'post',
'posts_per_page' => 10,
  'meta_query'=> array(
    array(
      'key' => 'wpcf-typeofgame',
      'compare' => '=',
      'value' => '5x5'
    )
  )

);
?>
<?php $loop = new WP_Query( $args); ?>

http://wordpress.org/extend/plugins/types/