HGH, we have FAM installed on our server.  Each workstation (client machine) performs a 'network install' of FAM; similar to the way in which a ProSeries install occurs.  All data files (FAM client files) are on the server drives which are shared and mapped to the client machines.  For us, it was the client machine's loss of the mapping to the server's shared drive - even if only for an instant - that created the problem.  In our case, this was due to a group policy setting.  The workstation/client machine was running the FAM program which was writing to a file on a shared, mapped-network drive.  A momentary disconnect of the mapped drive severed the FAM program's connection to the FAM client file.  That was enough to render the FAM client file useless.  Somewhere in your installation, your program may be disconnecting from the client file (could be due to a periodic virus scan...don't know) and that may be creating the problem.  It was for us.  For some reason, I thought FAM was MS Access (with modifications).  Not sure if the same would happen with a MS Access file.