Maybe a problems caused by SMB2? We had a similar issue at a client, they had SMB2 enabled on their network and it cause VFP to loose network connection once in a while for very short time, but enough to get "Error reading file" and also sometimes index corruption.

http://stackoverflow.com/questions/7007331/foxpro-sometime-doesnt-find-files-in-the-lan

>Hi friends:
>
>Last year I had the problem from time to time that a file wasn't found and my system used to créate it.
>
>But I lost data because file actually existed so I had to develope a "security" routine. File doesn't exist but It did before. I'm goin to retry but if error persist I'm going to créate it EMPTY. Are you sure what you're doing?
>
>As none of my clients can be sure and I waited a few seconds to retry I haven't had that problem again.
>
>What I thought was "Server fails"
>
>Now I have a similar trouble.
>
>SEEK SOMEKEY = "Error Reading file..." (sometimes DBF, sometimes CDX)
>
>USE SOMEFILE = "Error Reading file..."
>
>I say to myself: "Router, wire, electricity, server problem"
>
>But the point is if that was the problem ERROR shouldn't be registered cause DBF that register error in less of a second is on the server.
>
>I can do the same. Retry five times before letting error explode but I would like to know if that is possible, reasons for these kind of problems in differents machines, differents local servers (no Internet servers) and differents clients.
>
>My clients don't call me. I notice because an automatic mail is sent to me. They restart server and do nothing else. Just everything goes on ok.
>
>No reindex, no repair DBFs.
>
>If only one of them was the problem I would know is the machine or net, but this occurs in several cases.
>
>Often W7, almost never W XP
>
>Any idea?
>
>Thank you.
>
> Héctor