pgpoolAdmin keeps going straight back to it's login page

I'm trying to run pgpoolAdmin through nginx - it seems to be working properly, at least initially.

I've gone through the initial set-up, which works fine, but now after logging in every link takes me straight back to the login page. It also shows japanese text instead of english, despite picking english in the installation.

It seems to me just as if it was unable to save any user data, session information etc.

I have javascript/cookies enabled, so it's not that. The ownership of the folder is nginx, and so too is pgmgt.conf.php, so it shouldn't be a problem with permissions. One potential issue is that I can't seem to see any confirmation that php postgresql support is enabled in the php info screen, despite the correct package installed and in the config line.

Any ideas as to what's happening here?

The nginx rules are pretty standard:

server {

    # pg-pool admin

   listen       997;
   server_name  localhost;
   root      /opt/pgpooladmin;
   index     index.php;

   location ~ .php$ {
         fastcgi_pass_header Set-Cookie;
         fastcgi_pass   127.0.0.1:9000;
         fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
         fastcgi_param  PATH_INFO $fastcgi_script_name;
         fastcgi_index  index.php;
         include        fastcgi_params;
   }

}