PHP suddenly not recognising pg_connect

I restarted apache today and suddenly a site I managed stopped working.  It
seems php no longer recognises the pg_connect command.  I'm running
PostgreSQL 8.4.1 and PHP 5.2.11 on Gentoo.  I recompiled PHP just in case
I'd upgraded PostgreSQL before without recompiling PHP with it, but no luck.
 I've checked what gentoo says I've got installed, and it says that it used
postgres as one of the includes with dev-lang/php.
I've also noticed PHP has also dropped MySQL support.  Doing a phpinfo()
check, I've got --with-pgsql=shared showing and also mysql=shared,/usr'
'--with-mysql-sock=/var/run/mysqld/mysqld.sock'
'--with-mysqli=shared,/usr/bin/mysql_config, but there's no section for
PostgreSQL on the page, or MySQL.

I installed pgbouncer a couple days ago too, but I don't expect that's got
anything to do with this.

What's going on?

Thom