difficulty building PostgreSQL with PHP4?

I've just built Apache 1.3.17 on Free BSD, using php-4.0.1pl2 and linking
with the PostgreSQL 7.0.3 as a shared object.  I created a test database,
with proper permissions for the web server.  I can query it with psql, and
I see a socket as "/tmp/.s.PGSQL.5432=".

I also linked in mySQL support, which works correctly.

When I try accessing the posters database by calling
pg_Connect("dbname=test"), my web server doesn't even display a page, other
than "this page cannot be displayed" (in IE) or "page contains no data"
(Netscape).

The error log displays:
(null): Undefined symbol "_PQsetdbLogin" called from
httpd:/com/apache/libexec/libphp4.so at 0x8256498

A friend suggested calling pg_Connect with no arguments - if I do that, the
page displays with the error "Wrong parameter count for
pg_connect()".  This implies the postgres library was able to resolve with
php, and something else may be the problem when I add arguments.

Are there issues with PHP4?
Is there a problem building both postgres and mysql support?
Should I be using a static module build for PHP, rather than a DSO?

thanks.