error message

hi, i'm using access97 linked to postgres(6.4.2) tables through the new
v.6.4 odbc. i can open a form, it shows me data for an initial record, and
then bombs. here is the message in the log file -- i can't figure out why
it is bombing. does anyone have a clue?? do those "-" or "/" in various
"vinvnum" fields cause problems?? it shows valid data first, waits for a
second, and then bombs!

TIA, jt

conn=50745568, query='declare SQL_CUR0308FC60 cursor for SELECT
"vnum","vinvnum","vinvrecdt","vinvduedt","vinvamt","glnum","checkdt","ch
ecknum","ponum",'#S_C_H#' FROM "ap" WHERE "vnum" = 20000 AND "vinvnum" =
'13639 VOID' OR "vnum" = 20000 AND "vinvnum" = '138577-Void' OR "vnum" =
20000 AND "vinvnum" = '142185-SHOP' OR "vnum" = 20000 AND "vinvnum" =
'2Brother Credit 1/99' OR "vnum" = 20000 AND "vinvnum" = '37003 OFO-Chairs'
OR "vnum" = 20000 AND "vinvnum" = 'Aberdene, SD' OR "vnum" = 20000 AND
"vinvnum" = 'Adj for Nov' OR "vnum" = 20000 AND "vinvnum" = 'Adj for Oct
97' OR "vnum" = 20000 AND "vinvnum" = 'Agson 132289' OR "vnum" = 20000 AND
"vinvnum" = 'Air Trans''
ERROR from backend during send_query: 'ERROR: Unable to find an ordering
operator '<' for type unknown.
Use an explicit ordering operator or modify the query.'
conn=50745568, query='ABORT'
STATEMENT ERROR: func=SC_execute, desc='', errnum=1, errmsg='Error while
executing the query'

--------------------------------------------------------
----
hdbc=50745568, stmt=50920544, result=0
manual_result=0, prepare=1, internal=0
bindings=0, bindings_allocated=0
parameters=50911028, parameters_allocated=20
statement_type=0, statement='SELECT
"vnum","vinvnum","vinvrecdt","vinvduedt","vinvamt","glnum","checkdt","ch
ecknum","ponum",'#S_C_H#' FROM "ap" WHERE "vnum" = ? AND "vinvnum" = ? OR
"vnum" = ? AND "vinvnum" = ? OR "vnum" = ? AND "vinvnum" = ? OR "vnum" = ?
AND "vinvnum" = ? OR "vnum" = ? AND "vinvnum" = ? OR "vnum" = ? AND
"vinvnum" = ? OR "vnum" = ? AND "vinvnum" = ? OR "vnum" = ? AND "vinvnum" =
? OR "vnum" = ? AND "vinvnum" = ? OR "vnum" = ? AND "vinvnum" = ?'
stmt_with_params='declare SQL_CUR0308FC60 cursor for
SELECT
"vnum","vinvnum","vinvrecdt","vinvduedt","vinvamt","glnum","checkdt","ch
ecknum","ponum",'#S_C_H#' FROM "ap" WHERE "vnum" = 20000 AND "vinvnum" =
'13639 VOID' OR "vnum" = 20000 AND "vinvnum" = '138577-Void' OR "vnum" =
20000 AND "vinvnum" = '142185-SHOP' OR "vnum" = 20000 AND "vinvnum" =
'2Brother Credit 1/99' OR "vnum" = 20000 AND "vinvnum" = '37003 OFO-Chairs'
OR "vnum" = 20000 AND "vinvnum" = 'Aberdene, SD' OR "vnum" = 20000 AND
"vinvnum" = 'Adj for Nov' OR "vnum" = 20000 AND "vinvnum" = 'Adj for Oct
97' OR "vnum" = 20000 AND "vinvnum" = 'Agson 132289' OR "vnum" = 20000 AND
"vinvnum" = 'Air Trans''
data_at_exec=-1, current_exec_param=-1, put_data=0
currTuple=-1, current_col=-1, lobj_fd=-1
maxRows=0, rowset_size=1, keyset_size=0, cursor_type=0,
scroll_concurrency=1
cursor_name='SQL_CUR0308FC60'
----------------QResult Info
-------------------------------
CONN ERROR: func=SC_execute, desc='', errnum=110, errmsg='ERROR: Unable to
find an ordering operator '<' for type unknown.
Use an explicit ordering operator or modify the query.'
------------------------------------------------------------