You haven't been able to identify the correct users since Novell days. I think there is some NETBIOS stuff in DFW 5-7.2 that attempt to do this but as far as I know it only slow down the network rather than helping.
The problem with locking the database is most likely related to a problem with the network files.
You can delete the files with .LAN exstension and try again.
Written by DataEase 17/09/18 at 15:40:59DataEase for Windows 5.x and before...