My b2evolution Version: 3.3.3

Trying to restrict viewing of my blog unless you are a registered, logged-in user.

tried this: http://forums.b2evolution.net/viewtopic.php?t=17485

but i can't find a version of bopit to do the am:protected thing, and that $login_required = true; thing doesn't work in my index.php file. (Only have one blog and it runs off the index.php file so I'm assuming it's the correct stub file to being this to?)

I'm happy with just changing the default status of my posts/pages/etc to "protected", (via this http://forums.b2evolution.net/viewtopic.php?p=98923#98923 ) except that any visitor not logged in can still view the sidebar widgets on the main page.

Any help? Or at least a suggestion as to why adding

$login_required = true;

into the index.php file doesn't work?