Theme Group permissions are broken.

[ernestbuffington]

When you select groups and assign a theme to a group only members of that group should see the theme. As it sits no matter what group you assign a theme to all are viewable. If you select Admin only then only admins will see them, however, the groups select is not working the way it is supposed to. When a theme is assigned to a group then only members of that group should see those themes.