Jim,
I do not think this is related to transaction processing but then it may be.In the past, when I had this discussion on UT I was told that there is no way to avoid this kind of problem occasionally happening on peer to peer networks. I know this used to happen on FoxPro 2.5 and I looked forward to moving to VFP and using Transaction Processing so the problem would go away. Sadly as we both know it has not, though I do think that is happens with less frequency now. Because this only happens with a few of my customers ( 2 or 3 out of a base of over 1000) I tend to think it is more hardware or system related than anything. It would be very nice if VFP would police itself. However, I think that that was the intent with some changes in VFP 7 and they backfired.
A problem is a problem only as long as it has a possible solution. Lacking that, it becomes a FACT!