从 0.7.30 版本以来，33版本的改动包括如下内容：
*) Bugfix: a double response might be returned if the epoll or rtsig methods are used and a redirect was returned to a request with body.
*) Bugfix: the $sent_http_location variable was empty for some redirects types.
*) Bugfix: a segmentation fault might occur in worker process if "resolver" directive was used in SMTP proxy.
*) Feature: now a directory existence testing can be set explicitly in the "try_files" directive.
*) Bugfix: fastcgi_store stored files not always.
*) Bugfix: in geo ranges.
*) Bugfix: in shared memory allocations if nginx was built without debugging.
*) Change: now the "try_files" directive tests files only and ignores directories.
*) Feature: the "fastcgi_split_path_info" directive.
*) Bugfixes in an "Expect" request header line support.
*) Bugfixes in geo ranges.
*) Bugfix: in a miss case ngx_http_memcached_module returned the "END" line as response body instead of default 404 page body; the bug had appeared in 0.7.18.
*) Bugfix: while SMTP proxying nginx issued message "250 2.0.0 OK" instead of "235 2.0.0 OK"; the bug had appeared in 0.7.22.