Error in declaring %rowtype for recurrence

Dear Friends,

Postgres 7.3.4 on RH Linux 7.2

I am having an table name recurrence under the schema crm. While I refer it as %rowtype I have error msgs.

CREATE OR REPLACE FUNCTION crm.fn_rowtypetest() RETURNS varchar AS
'DECLARE
rec_recurrence crm.recurrences%rowtype;
BEGIN
FOR rec_recurrence IN SELECT * FROM crm.recurrences LOOP
RAISE NOTICE 'Hai';
END LOOP;
RETURN 'DONE';
END;'
LANGUAGE 'plpgsql' VOLATILE;

while I execute
select crm.fn_rowtypetest()

WARNING: plpgsql: ERROR during compile of fn_rowtypetest near line 0

ERROR: cache lookup for type 0 of recurrences.........pg.dropped.16........ failed

The same function works if I declare that via an record type

CREATE OR REPLACE FUNCTION crm.fn_rowtypetest() RETURNS varchar AS
'DECLARE
rec_recurrence record; ------------------------------------------------------------------------------------------ Note the change here
BEGIN
FOR rec_recurrence IN SELECT * FROM crm.recurrences LOOP
RAISE NOTICE 'Hai';
END LOOP;
RETURN 'DONE';
END;'
LANGUAGE 'plpgsql' VOLATILE;

Why is that so? Anyone can please clear me.

Regards
Kumar