Transfer 8.3 to 8.4 - FUNCTION gtsq_in(cstring) does not exist

Hi
I'm transferring a database from 8.3 to 8.4 and I've done a pg_dump of the
db schema on 8.3. When I pg_restore it to 8.4 I get the following:

pg_restore: creating FUNCTION gtsq_in(cstring)
pg_restore: [archiver (db)] Error from TOC entry 550; 1255 4231868780
FUNCTION gtsq_in(cstring) postgres
pg_restore: [archiver (db)] could not execute query: ERROR: could not find
function "gtsq_in" in file "/usr/lib/postgresql/8.4/lib/tsearch2.so"
Command was: CREATE FUNCTION gtsq_in(cstring) RETURNS gtsq
AS '$libdir/tsearch2', 'gtsq_in'
LANGUAGE c STRICT;

I'm getting the same error when it tries to create function
gtsq_out(cstring), gtsvector_out(cstring) and gtsvector_in(cstring) as well

I've run the tsearch2.sql in /usr/share/postgresql/8.4/contrib but still no
go. I can't seem to find any info on web either.

Rebecca