Unwired Server has mechanisms for protecting data from conflicting changes during synchronization.
If a mobile business object (MBO) performs an update operation, the device sends additional parameters to the server that contain the original values of the database columns mapped to the object's parameters. These original values are shared with the enterprise information system (EIS) server in specially-named arguments. That is, if an argument is named A, and if the original value is available, it is provided in the argument named sup__oldvalue__A. By checking whether or not the original values has become stale, the EIS update operation can avoid conflicting updates.
Because the current lname ('Jane') is not same as sup__oldvalue__fname ('Joe') the update for D2 does not occur.