Either I broke PostgreSQL or I found an ODBC bug

I am using the ODBC provider [8.02.05.0000] to connect my postgresql database [8.2.5] with my MS ACCESS XP front-end.

This is what I am seeing:  When I issue a select statement from with-in ms-access, the Boolean field that contain null
valuesare returning as false( as 0 in the datasheet view).  My expectation is that null Boolean values display as null
ratherthan false.  When I issue the same query with-in psql the null boolean values correctly display as NULL. 

A while back I applied the following directions to  MS-Access' [yes/no] type to create a better mapping with
PostgreSQL'sBoolean type.  I don't know if these direction are redundant to what is already provided in the ODBC
provider. Perhaps the operator that I've created is causing the problem I am seeing. 
http://archives.postgresql.org/pgsql-odbc/2006-09/msg00103.php


FROM MS-Access:
SELECT did, chktagdesc
 WHERE did = 13601 AND chktagdesc IS NULL;
did     |chktagdesc
--------+-----------
13601   |     0

FROM psql
proj02u20411=> select did, chktagdesc from docs.lfworkscope where did = 13601 and chktagdesc is null;
  did  | chktagdesc
-------+------------
 13601 |
(1 row)

Can anyone where find where this problem is coming from?

Regards, Richard Broersma Jr.