WP_Query compare not working

Hello,

I set this arguments for WP_Query

$args = array(
    'nopaging' => false,
    'posts_per_page' => 3,
    'paged' => '1',
    'post_status' => 'publish',
    'category_name' => 'ideas',
    'orderby' => 'post_date',
    'order' => 'DESC',
    'meta_query'  => array(
      'relation' => 'AND',
      array(
        'key' => 'idea_language',
        'value' => $domkey
      ),
      array(
        'key' => 'idea_visibility',
        'value' => 8,
        'compare ' => '!=',
        'type' => 'NUMERIC'
      )
    )
  );

but the != compare is not working.
The query I get is:

SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) INNER JOIN wp_postmeta AS mt1 ON (wp_posts.ID = mt1.post_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (4) ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') AND ( (wp_postmeta.meta_key = 'idea_language' AND CAST(wp_postmeta.meta_value AS CHAR) = 'eu') AND (mt1.meta_key = 'idea_visibility' AND CAST(mt1.meta_value AS SIGNED) = '8') ) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 3

Any help is really appreciated.

Regards,
Spyros