>My initial thought was that it referred to optimistic locking in VFP, but obviously not. The site in question is using Samba and there is an entire literature on the failures of OPLOCK when using Samba. I passed the info along to the site administratior and hopefully he will be able to turn if off and solve the problem. Thanks for your help!

Did you also consider the 2 'dummy' fields?

I know it sounds a strange "solution". But it was determined - with the help of MS Support if I remember correctly - by a VERY early experiencer of the problem. I remember his reporting that the incidence went WAY down after that fix.

You should also make sure that SET TABLEVALIDATE is set to detect the condition. It will not "fix" the problem but it will help you to prevent the loss of a record. It can be set to generate an error if the logical file size differes from the physical file size.

good luck