Changes with nginx 0.7.24                                        01 Dec 2008
    *) Feature: the "if_modified_since" directive.
    *) Bugfix: nginx did not process a FastCGI server response, if the
       server send too many messages to stderr before response.
    *) Bugfix: the "$cookie_..." variables did not work in the SSI and the
       perl module.
-- 
Igor Sysoev
http://sysoev.ru/en/