>>>>>Is it a typo? You put ID.grno instead of ID1.grno
>>>>>
>>>>>Also check if you have rules or triggers in PS1 table.
>>>>>
>>>>Thanks, it was typo when I simplified the UPDATE statement. NO rules or triggers in the tables.
>>>
>>>The statement looks OK to me - are you sure you're updating the table you are thinking you're updating? Could it be another table included into exe or somewhere else in the path?
>>>
>>>You may also try using replace command instead.
>>
>>I updated the right table, because when I ignored the error message, the data is there.
>>Yes, I can use the replace command.
>>Thanks
>
>It could have also been a bug in VFP, but even if it is, there is no chances it will be corrected.

So it looks like I need to change the code and use REPLACE.