>>>>Tommy, were you getting the error on use (add/edit)? Or on the creation of the
>>>>initial INDEX? I thought you were getting it occasionally on the INDEX ON
>>>>command itself.
>>>
>>>The error would always occur on the line of code that would assign the value
>>>of 5 to 'status' of the new record in ss_io.
>>
>>
>>So the SET value of CENTURY at that point differed from the value when the INDEX was created?
>
>
>No, the same. SET CENTURY ON and SET STRICTDATE TO 0, in the old and new code


I guess I'm not understanding how this is happening then. I could see if the CENTURY was ON and it created an index key along the lines of "MM/DD/YYYY" and then you tried to create a key which was "MM/DD/YY" as possibly generating an error. And I could see if it created a key with CENTURY OFF using "MM/DD/YY" and then you tried to create a key later with it ON which was "MM/DD/YYYY" and definitely generating an error.

But how does it generate an error under any condition when the key is the same length? Seems like a bug in VFP9SP1 and not anything wrong with your logic or usage.