cached plan issue in trigger func

I thought we had fixed this in 8.3:
   cap=# create table t1 (t varchar(40));   CREATE TABLE   cap=# create table t2 (t varchar(40));   CREATE TABLE
cap=#create function t1trig() returns trigger language plpgsql as   $$ begin insert into t2 values(new.t); return null;
end;$$;   CREATE FUNCTION   cap=# create trigger t1trigger after insert on t1 for each row   execute procedure
t1trig();  CREATE TRIGGER   cap=# insert into t1 values('a');   INSERT 184789343 1   cap=# alter table t1 alter column
ttype text;   ALTER TABLE   cap=# alter table t2 alter column t type text;   ALTER TABLE   cap=# insert into t1
values('b');  ERROR:  type of "new.t" does not match that when preparing the plan   CONTEXT:  PL/pgSQL function
"t1trig"line 1 at SQL statement   cap=#
 



cheers

andrew