>>>I'm updating a view (buffering=5), even go top, the TABLEUPDATE(2,.T.) returns .t., but trying to change buffering results in an error.
>>>
>>>What am I doing wrong, or how do I get it right?
>>
>>Check the return value of TABLEUPDATE, if it returns .F., use AERROR to see why.
>>
>>If it returns true, but it appears that some records were not updated, I would guess you have a problem with primary keys?
>
>Right you are, it's the PK.
>Now the question remains, what's the fastest way to find the offending record(s)?
>

You shouldn't have to go through all that to find duplicate PKs. Your base table should have a constraint on its PK so that duplicates are not allowed at all.

PS, the code you posted never does a GO to the next modifies record.