Defining capabilities for custom post type in WordPress

You code seems to be correct. Try the following instead.

$args = array( 'labels' =>
 $labels, 'public' =>
 true, 'publicly_queryable' =>
 true, 'show_ui' =>
 true, 'query_var' =>
 true, 'rewrite' =>
 true, 'hierarchical' =>
 false, 'menu_position' =>
 null, 'supports' =>
 array(itle'), 'capability_type' =>
 'video'
);

Update:

You have to do some extra steps before making it work with the members plugin. See this forum post from Justin Tadlock (developer of the members plugin). http://wordpress.org/support/topic/anyone-managed-to-get-custom-post-types-capabilities-working/page/2#post-1593534

This plugin seems to be doing it automatically: http://wordpress.org/extend/plugins/map-cap/