>Hello Al,
>
>I have been doing a lot of research on this problem and may have narrowed it to some phenomenon known as Opportunistic Locking (oplock). See Q296264. These are machine settings, rather than software actions.
>
>So, in my particular situation, my main screen has a BufferMode setting of 2, which is called "Optimistic Locking" in the VFP Documentation. The table has a BufferModeOverride setting of 1, which defaults the setting to the one shown on the form.
>
>The question is do these two factors relate to each other, and to the problem of my disappearing records? Should I change the BufferMode in the form to Pessimistic, or should I go into the server and workstations to change the machine settings? Or should I change them both?
>
>Any light you could shed on this would be greatly appreciated.

Although they seem similar these two things are effectively not related. Opportunistic locks (oplocks) are an OS-level performance enhancement to the standard NetBIOS/SMB file/record locking mechanisms. VFP BufferMode is an application-level setting that determines how records are updated. The pessimistic setting is not often used because it locks records for long periods of time which causes concurrency issues in multiuser systems. A BufferMode of 0 or 2 is normal for VFP applications and is unlikely to be the cause of your problem.

MS staff have not, to the best of my knowledge, spoken up here (or elsewhere) on how oplocks on both server and workstations interact with VFP, whether they cause any data buffering as well as "enhanced" lock handling. So it may be worth disabling them on both server and (all) workstations.

Some apps benefit from oplocks being on: FYI: NT/W2K Opportunistic Locking Thread #462793 Message #462793

There was a setting on Windows NT that may be worth making, don't know if it still applies to W2K: http://support.microsoft.com/default.aspx?scid=kb;en-us;124916