core dumps and packaged procedures

WHEN -
Running forms 3.0.16.12.9
PLSQL 01.00.42.00.01
against ORACLE 7.1.6.2.0
PLSQL 2.1.6.2.0

--
a call to a packaged procedure passing in a literal null
e.g.
--
   DEFINE PROCEDURE

      NAME = STORE_DXREG
      DEFINITION = <<<
      procedure STORE_DXREG (P_ICD_CODE in varchar2) is
      --
      -- ICD_TIT    K_ICD9LIST.ICD9_TITLE%type;
         ICD_TIT    varchar2(200);
      begin
         K_COD_PKG.K_GET_ICD9_TITLE(P_ICD_CODE,
                                    'ALL',
                                    ICD_TIT,
                                    null);
      end;


      >>>


   ENDDEFINE PROCEDURE
--
CAUSES A COREDUMP - segmentation error

ANY IDEAS ??