In order to get this to work with my theme I had to modify my themes sidebar.php file to look like this:
[ Moderator Note: Please post code or markup snippets between backticks or use the code button. ]
<?php
$is_custom = get_post_meta($post->ID, 'is_custom', true );
if( $is_custom == 'y'){
dynamic_sidebar('page-sidebar-' . $post->ID);
} else {
dynamic_sidebar('sidebar-primary');
}
?>
I'm using the Roots theme: http://www.rootstheme.com/