Can't load plpgsql.so error

Hi

I'm a Postgres newbie, so bear with me :o)

I've created a trigger, which calls a procedure written in plpgsql,
The trgiger is called on INSERT on a table. However, when I try to do
an insert on the table, using psql, I get a message saying that the
load of /usr/local/pgsql/lib/plpgsql.so failed because shared object
libpq.so.2 not found. Yet the very fact that I'm running psql means
that it was found...

Any hints, clues, docs. greatly appreciated.

The system is

FreeBSD 4.0-RELEASE
Postgres 6.5.3

I use ldconfig to set the search paths (using LD_LIBRARY_PATH didn't
help).

Thanks

Adrian