Problems with Access XP and text primary keys

I've been using Postgres 8.0rc5 with the pgsqlODBC 8.00.00.03 driver and am
having some problems.

The database works correctly for some time but suddenly and for no reason I
can find I get #Deleted in some of the fields. These tables seem to be those
which have text primary keys. I've looked at the psqlodbcXXXX.log and it
seems that I get:

conn=162845400, query='SELECT "mw"."users"."user_name" FROM "mw"."users" '
[ fetched 13 rows ]

conn=162845400, query='SELECT
"user_name","entered_ts","entered_user","last_changed","last_user","full_name","area_id","xmin"
FROM "mw"."users" WHERE "user_name" = 'b' OR "user_name" = 'c' OR
"user_name" = 'm' OR "user_name" = 'b' OR "user_name" = 'p' OR "user_name" =
't' OR "user_name" = 'j' OR "user_name" = 'r' OR "user_name" = 'f' OR
"user_name" = 'j''
[ fetched 0 rows ]

conn=162845400, query='SELECT
"user_name","entered_ts","entered_user","last_changed","last_user","full_name","area_id","xmin"
FROM "mw"."users" WHERE "user_name" = 'p' OR "user_name" = 'p' OR
"user_name" = 'j' OR "user_name" = 'j' OR "user_name" = 'j' OR "user_name" =
'j' OR "user_name" = 'j' OR "user_name" = 'j' OR "user_name" = 'j' OR
"user_name" = 'j''
[ fetched 0 rows ]

instead of when working correctly:

conn=170998744, query='SELECT "mw"."users"."user_name" FROM "mw"."users" '
[ fetched 13 rows ]

conn=170998744, query='SELECT
"user_name","entered_ts","entered_user","last_changed","last_user","full_name","area_id","xmin"
FROM "mw"."users" WHERE "user_name" = 'btrewern' OR "user_name" =
'chappellj' OR "user_name" = 'mcwilliamsf' OR "user_name" = 'ben' OR
"user_name" = 'postgres' OR "user_name" = 'timc' OR "user_name" = 'jasonc'
OR "user_name" = 'robh' OR "user_name" = 'francism' OR "user_name" =
'janeh''
[ fetched 10 rows ]

conn=170998744, query='SELECT
"user_name","entered_ts","entered_user","last_changed","last_user","full_name","area_id","xmin"
FROM "mw"."users" WHERE "user_name" = 'pons_temp' OR "user_name" = 'pauls'
OR "user_name" = 'jeremyw' OR "user_name" = 'jeremyw' OR "user_name" =
'jeremyw' OR "user_name" = 'jeremyw' OR "user_name" = 'jeremyw' OR
"user_name" = 'jeremyw' OR "user_name" = 'jeremyw' OR "user_name" =
'jeremyw''
[ fetched 3 rows ]

The table "mw"."users" is created as:

CREATE TABLE users
(
  user_name short_text_dom PRIMARY KEY,
  entered_ts timestamp DEFAULT ('now'::text)::timestamp(6) with time zone,
  entered_user short_text_dom DEFAULT "current_user"(),
  last_changed timestamp,
  last_user short_text_dom,
  full_name text,
  area_id int4 NOT NULL
);

and

"mw"."short_text_dom" is:

CREATE DOMAIN short_text_dom
  AS varchar(250);

Does anyone have any ideas?

Regards,

Ben Trewern