Postgre/PHP installation woes

[Danny O'Brien <dannyo@steinrogan.com>]

Any postgre experts out there? We have a PHP4 site that worked fine under a previous RedHat build, but we just can't get it working on this Debian build.

Here's what we're running:

Debian 3.0r1 "woody"
Kernel 2.4.18-bf2.4
Apache 1.3.26-0woo
postgres 7.2.1-2wood
php 4.1.2-6wood

We've applied a script sent to us by the original programmers, that installed several logins and passwords.
But when we go to login to our PHP site, our login is rejected and we get the following error:

Warning: Supplied argument is not a valid PostgreSQL link resource in <path>/auth.php on line 10

Line 10 in auth.php looks like this:

$result = pg_exec( $link, $sql );

We've attempted to log in many times, so we know we're not mis-typing the password. Is the login prompt not hitting the database?

TIA for any suggestions,

Danny O'Brien