I am unable to find anywhere within Admin that allows for me (SuperUser) to set permissions for any user as editor, moderator or admin. I saw another question that was asking about the same thing regarding WP and so I thought that I'd start this as a separate question. But in that other question an answer was provided that indicated that you go to the user's page and use a pull-down menu to change permission levels. I have checked the user pages and at least in 1.5.4 there doesn't appear to be a pull down menu.
