Apache mod pg_auth for CentOS - help with module
 

We are trying to replace our old servers (running Fedora5 with some updated hardware. CentOS 5.2 is installed, and as I copy over conf files, I hit a snag. Starting apache it complained with;

Starting httpd: Syntax error on line 840 of /etc/httpd/conf/httpd.conf:
Invalid command 'AddExternalAuth', perhaps misspelled or defined by a module not included in the server configuration

I looked around, actually found/installed an RPM which thought it was it;
mod_auth_pgsql-2.0.3-2.3.1

But same error. There is a module in apache/mod's mod_auth_pgsql.so which I tried to load via LoadModule but it just fails with another error. The conf on the fedora shows;
AddExternalAuth pg_auth /home/user/local/apache2/bin/pg_auth
SetExternalAuthMethod pg_auth pipe

AddExternalAuth PostgresTag Postgres:
SetExternalAuthMethod PostgresTag function

So that is where I am stuck right now. Not 2 familiar with apache mods, but any help or suggestions are appreciated.