add_action('save_post', 'create_tags' );

define( 'FLOWPLAYER_CORE_JS', FLOWPLAYER_DIR . 'flowplayer-3.2.6.min.js' );
define( 'FLOWPLAYER_PLAYER_SWF', FLOWPLAYER_DIR . 'flowplayer-3.2.7.swf' );
define( 'FLOWPLAYER_CONTROLS_SWF', FLOWPLAYER_DIR . 'flowplayer.controls-3.2.5.swf' );

wp_register_script( 'flowplayer', FLOWPLAYER_CORE_JS );
if ( !is_admin() ) wp_enqueue_script( 'flowplayer' );

add_filter( 'media_send_to_editor', 'yacc_media_send_to_editor', 10, 2 );
function yacc_media_send_to_editor( $html, $id ) {
    $attachment = get_post( $id );
    $mime_type = $attachment->post_mime_type;
    if( substr( $mime_type, 0, 5 ) == 'video' ) {
      $html = '[flowplayer video="' . $attachment->guid . '"]';
    }
   return $html;
}

add_shortcode( 'flowplayer', 'yacc_flowplayer' );
function yacc_flowplayer( $atts ) {
   extract( shortcode_atts( array( 'video' => '' ), $atts ) );
   if( $video == '' ) return;
   $script = '<script>
      flowplayer("player", "' . FLOWPLAYER_PLAYER_SWF . '", ({
         clip:  {
                  autoPlay: false
},
         plugins: {
            controls: {
backgroundImage: {url: \'' . путь к тумбе.jpg . '\',}  и так пробовал backgroundImage: url(путь к тумбе.jpg)

               url: \'' . FLOWPLAYER_CONTROLS_SWF . '\',
            }
         }
      }))
   </script>';
   return '<p><a href="' . $video . '" style="display:block;width:690px;height:390px;border:1px solid #0024B8" id="player"></a>' . $script . '</p>';
}

...
controls: {      
   // setup a background image
   background: 'url(/img/player/skin_leather.png) no-repeat',
...

function yacc_nav_menu_items( $items ) {
   if( is_admin() && $GLOBALS['pagenow'] == 'nav-menus.php' ) return $items;
   $items[0]->classes[] = 'first';
   $items[count( $items ) - 1]->classes[] = 'last';
   return $items;
}
add_filter( 'wp_get_nav_menu_items', 'yacc_nav_menu_items' );