mod_auth_request + php5-fpm gives error 504 on POST requests, GET requests are okay

[refghbn]

Setup: php5-fpm listening on socket + nginx 1.2.6

Wanted to use mod_auth_request for www authentication. Works fine for GET
requests, POST requests time out with error 504.

Error log:
2013/02/24 00:13:03 [error] 24004#0: *13 auth request unexpected status: 504
while sending to client, client: 80.187.106.XXX, server: xxx.net, request:
"POST /test.php HTTP/1.1", host: "xxx.net", referrer:
"https://xxx.net/test.php"

With GET, as stated, and when testing the subrequest script directly,
everything works fine. Gives 201/401 header, empty body as it should.

          location ~ \.php$ {
  
                  root /var/www;
 
                  fastcgi_pass    unix:/var/run/php5-fpm.sock;
                 fastcgi_index  index.php;
                 fastcgi_intercept_errors on;
                  error_page 404 /index.html;
  
                  fastcgi_param DOCUMENT_ROOT   /var/www;
                  fastcgi_param SCRIPT_FILENAME
/var/www$fastcgi_script_name;
                  fastcgi_param PATH_TRANSLATED
/var/www$fastcgi_script_name;
  
                 include /etc/nginx/fastcgi.conf;
 
                 auth_request /authenticator/www.php;
         }
 
         location = /authenitcator/www.php {
                 fastcgi_pass unix:/var/run/php5-fpm.sock;
                 fastcgi_param SCRIPT_FILENAME
/var/www$fastcgi_script_name;
                 fastcgi_param PATH_TRANSLATED
/var/www$fastcgi_script_name;
         }

Does anyone have an idea?

/refghbn

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,236524,236524#msg-236524