Is it a multi-user system? A record could be inserted after your locate fails and prior to your insert.

>I just discovered that one of my table has duplicate records. I am trying to
know what is causing this.
>
>The application using it only has one place in the code where a record can be inserted. That is based on a condition. If the LOCATE is NOT FOUND, then I will INSERT INTO table.
>
>The code is like this:
>

>SELECT LOGIN
>LOCATE FOR NOMEMBER=lnNoMember AND NOCLIENT=lnNoClient
>IF FOUND()
>   do something
>   ELSE
>   INSERT INTO LOGIN (NOMEMBER,NOCLIENT,...) VALUES (lnNoMember,lnNoClient,...)
>ENDIF
>

>
>So, assuming the insertion of the duplicated record is done from here, it means the LOCATE fails. If that is the case, it would be because of an index corruption.
>
>I was wondering if someone already had a situation like that. Or, if someone might have an idea what else can cause this.