PLS-00801: internal error [22914]

I encounter the following error whene using a variable in
the where clause of a table(cast) select.

(1): PLS-00801: internal error [22914]

I have included all pertinent info below.


/******************************/
----create object type
/******************************/
CREATE OR REPLACE
type wpa_staging_type as object
( Entity number,
  Prod_type varchar2(30),
  Prod_rel NUMBER,
  Serial_id number);
/

/******************************/
----create table of object type
/******************************/
CREATE OR REPLACE
type wpa_staging_tab is table of wpa_staging_type;
/

/******************************/
--- package spec
/******************************/
create or replace PACKAGE     TEST_TS_PKG IS

PROCEDURE Test_it;
 temp_var number;
 wp_staging_type wpb_staging_tab := wpb_staging_tab(wpb_staging_type(1,'1',1,1)
                                    ,wpb_staging_type(2,'2',2,2));

END test_ts_pkg; /* End Package Specification test_ts_pkg */
/

/******************************/
-- this works
/******************************/
create or replace PACKAGE BODY     TEST_TS_PKG IS
PROCEDURE Test_it is
 i NUMBER;
BEGIN
  SELECT max(Entity)
  INTO i
   FROM TABLE(CAST(wp_staging_type AS wpb_staging_tab)) WHERE Prod_type=1;
  dbms_output.put_line(substr('Value of i ='||i ,1,255));

   EXCEPTION
    WHEN OTHERS THEN
        RAISE;
END Test_it;  
END test_ts_pkg;


/******************************/
-- this this gets "(1): PLS-00801: internal error [22914]" during compile
/******************************/
create or replace PACKAGE BODY     TEST_TS_PKG IS
PROCEDURE Test_it is
 i NUMBER;
BEGIN
  SELECT max(Entity)
  INTO i
   FROM TABLE(CAST(wp_staging_type AS wpb_staging_tab)) WHERE Prod_type=temp_var;
  dbms_output.put_line(substr('Value of i ='||i ,1,255));

   EXCEPTION
    WHEN OTHERS THEN
        RAISE;
END Test_it;  
END test_ts_pkg;