open /conf/_advanced.php and on line 72, you'll see this :

/**
 * Comments: Set this to 1 to require e-mail and name, or 0 to allow comments without e-mail/name.
 * @global boolean $require_name_email
 */
$require_name_email = 1;

oops, I think I stuffed it up :S.

I got this error:

Parse error: parse error, unexpected T_IF in /home/miso/public_html/b2/conf/_advanced.php on line 1

you have a space or blank line on line one ??

Fixed :)