Error loading dynamic library

I've experienced a problem installing the OpenFTS searching package
into PostgreSQL which currently has me baffled and I'd be grateful for
any assistance. I'm working under Mac OS X 10.2.6 and have the
following installed:

PostgreSQL 7.3.3
PERL 5.006
DBI 1.37
DBD-Pg 1.01
tsearch 2
OpenFTS 0.34

Everything worked fine up until attempting to create the custom OpenFTS
functions. For example the following query:

CREATE FUNCTION relor (float4, float4, int4, int4, int4, _text)
RETURNS float4
AS '/usr/local/pgsql/lib/openfts'
LANGUAGE 'C';

results in an error message: "ERROR: Load of file
/usr/local/pgsql/lib/openfts.so failed: no error message available"

Not very informative! The file is in the appropriate place and appears
to have the correct permissions and other dynamic libraries in the same
folder (eg tsearch.so) load without problem.

Anyone got any idea what's going on here? Could it be some type of
version incompatibility?

Thanks

Nick Oates
Technical Director
the OTHER media Ltd
London