[_ck_]

bb_is_user_logged_in() is right there, still in 1.0.1

The problem is you are checking too early, right when the plugin loads which is too soon.

A user is not determined as logged in until bb_init happens. So you have to make a mini-plugin

add_action('bb_init','check_login');

function check_login() {

if(!preg_match("/bb-login.php/", $_SERVER["SCRIPT_NAME"]) && !bb_is_user_logged_in()) {

header("Location: " . $bb->uri . "bb-login.php");

die("Authorisation required.");

}

}