Error in PLpgSQL with SELECT INTO and composite types

Tested on 8.2, 8.3 and CVS HEAD:

CREATE TYPE atype AS (a int);
CREATE TYPE btype AS (compcol atype);

CREATE FUNCTION foofunc() RETURNS void AS $$
  declare
   avar atype;
   bvar btype;
begin
   SELECT '("(1)")'::btype INTO bvar;  -- Should work, but errors
end;
$$ LANGUAGE plpgsql;

SELECT foofunc();

Gives error:

ERROR:  invalid input syntax for integer: "(1)"
CONTEXT:  PL/pgSQL function "foofunc" line 6 at SQL statement

Surely assigning a value of btype to a variable of the same type should
always work..

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com