Error during a dump (ts_selectivity, not found)

Hello all,

I am trying to restore a database on a server from a dump taken from a
different server, but I get the following error:

==============================================================================================================

# pg_restore -Upgsql -d db14
/mnt/backup/__initial_move__/db01_20110114.dump
Password:
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 25; 1255 2299293
FUNCTION tsmatchsel_wrapper(internal, oid, internal, integer) pgsql
pg_restore: [archiver (db)] could not execute query: ERROR: could not
access file "$libdir/ts_selectivity": No such file or directory
Command was: CREATE FUNCTION tsmatchsel_wrapper(internal, oid,
internal, integer) RETURNS double precision
LANGUAGE c
AS '$libdir...
pg_restore: [archiver (db)] could not execute query: ERROR: function
public.tsmatchsel_wrapper(internal, oid, internal, integer) does not exist
Command was: ALTER FUNCTION public.tsmatchsel_wrapper(internal,
oid, internal, integer) OWNER TO pgsql;
pg_restore: [archiver (db)] Error from TOC entry 2189; 2617 2299294
OPERATOR @-@ pgsql
pg_restore: [archiver (db)] could not execute query: ERROR: function
tsmatchsel_wrapper(internal, oid, internal, integer) does not exist
Command was: CREATE OPERATOR @-@ (
PROCEDURE = ts_match_qv,
LEFTARG = tsquery,
RIGHTARG = tsvector,
COMMUTATOR = @-@,
...
pg_restore: [archiver (db)] could not execute query: ERROR: operator
does not exist: tsquery public(dot)(at)-@ tsvector
Command was: ALTER OPERATOR public(dot)(at)-@ (tsquery, tsvector) OWNER TO
pgsql;
pg_restore: [archiver (db)] Error from TOC entry 2185; 2617 2299295
OPERATOR @-@ pgsql
pg_restore: [archiver (db)] could not execute query: ERROR: function
tsmatchsel_wrapper(internal, oid, internal, integer) does not exist
Command was: CREATE OPERATOR @-@ (
PROCEDURE = ts_match_vq,
LEFTARG = tsvector,
RIGHTARG = tsquery,
COMMUTATOR = @-@,
...
pg_restore: [archiver (db)] could not execute query: ERROR: operator
does not exist: tsvector public(dot)(at)-@ tsquery
Command was: ALTER OPERATOR public(dot)(at)-@ (tsvector, tsquery) OWNER TO
pgsql;

WARNING: errors ignored on restore: 6
==============================================================================================================

I searched for the library ts_selectivity, but all in vain.

Any advice/hint is very much appreciated.

Best Regards,
Ahmed Ossama