i remember trying to do this and it also not working. The solution i came up with was to remove "the public" from having permission ot read my site. Another option, which is incredibly simple and i haven't tested it for hacks - though i use it on my development server is to simply require a user_id greater than 0 on you master template. i.e. [ad_maybe_redirect_for_registration] or something similar. Of course you need to disable this on the actual login page.
