Derby DB : Replication Error

I am trying to setup replication b/w two Derby databases. Its embedded with an application. Configuration for replication is done as per the documentation here

When the application tries to start master instance, I get to see the following message. There is some exchange happening on the replication port b/w master & slave. But master quits with the message. Per the documentation,before starting master, the database is copied to the slave location. And no transaction happens in master after that. What does the message ( mismatch in log instance) mean? What could I be missing?

 Lost DB connection URL= jdbc:derby:db/NMS;startMaster=true;slaveHost= + REASON= The log files on the master and slave are not in synch for replicated database 'db/NMS'. The master log instant is 1:200335, whereas the slave log instant is 1:196097. This is fatal for replication - replication will be stopped.: