Add menu page issues (permissions & position)

you can do something like:

// create your own page
    add_menu_page('my-page', 'My Page', 'My Page', 'parent-slug', 'my_plugin_options', '', '10');

// create the subpage under my-page
    add_submenu_page('parent-slug', 'Sidebars', 'Sidebars', 'manage_options', __FILE__, array('sidebar_generator','admin_page'));

Note that the last parameter on add_menu_page is a 10. The higher the number the lower the position of the menu item.

HTH