No my customers are not VFP developer's but, the VFP applications they are running provide the ability to create and modify reports. Which is what you indicated was the problem. You also mentioned this was a problem with the coremeta.fpt. That leads me to believe the problem could potentially be with any and all memo files not just reports.

Is this only an issue when you are on the network? Are all the files subject to corruption on a file server or stored locally? You indicated there is a repeatable process to duplicate the problem. If so have you tried these steps on another machine?

I don't deny the problem could be Kaspersky but it could also be a lot of other things as well. This could be a hardware issue on the server or development machine or even a bad Ethernet connection.