Not replacing my default sidebar

I have guest sidebar disabled, and settings set to replace ‘sidebar,’ the default sidebar on my theme (I’m using the theme Simple Catch). I have the sidebars per user role set up, however the default sidebar never gets replaced. Please help 🙁 This plugin is exactly what I’m looking for if only it could work

http://ww.wp.xz.cn/extend/plugins/sidebar-per-user-role/