not able to setup tsearch2 synonym dictionary

Hi ,

I am trying to setup a synonym dictionary setup using instructions in

http://people.planetpostgresql.org/mha/index.php?/archives/118-Custom-synonym-dictionaries-in-tsearch2.html

after following all the steps lexize is not doing the expected eg

tradein_clients=# SELECT * from public.pg_ts_dict where dict_name='pg_dict';
-[ RECORD 1 ]---+-------------------------------------------
dict_name | pg_dict
dict_initoption | /opt/usr/local/pgsql/share/contrib/pg_dict
dict_comment | pg-specific dictionary
dict_init | syn_init(internal)
dict_lexize | syn_lexize(internal,internal,integer)

tradein_clients=# \!cat /opt/usr/local/pgsql/share/contrib/pg_dict
postgresql postgres
pgsql postgres
postgre postgres
tradein_clients=# \pset null NULL
Null display is "NULL".
tradein_clients=# select
lexize('pg_dict','postgresql'),lexize('pg_dict','pgsql');
-[ RECORD 1 ]
lexize | NULL
lexize | NULL

The expected result is

lexize| {postgres}
lexize| {postgres}

can any one pls tell where things might have gone wrong?

regds
mallah