Using Version 1.2 with WordPress 3.5.1 Network.
I installed the Plugin, activated it for the network and selected a available sidebar on the options page. But when i select a sidebar in the meta box and update the page, there is no modification in the frontend. The sidebar "pages" will be shown furthermore, nevertheless I replaced it.
In the Debug-Mode there is a notice in the meta box beside the Editor: "Notice: Undefined index: pages in /var/customers/webs/netberg/cms/wp-content/plugins/custom-sidebars/metabox.php on line 2" (pages is the ID of the sidebar)