Replication not working

I configured master slave replication and it worked fine however it stops working after 5 min or so! Although slave status show that replication is fine, however whatever I insert in master isn't replicating in slave

This is the tutorial I followed http://www.tecmint.com/how-to-setup-mysql-master-slave-replication-in-rhel-centos-fedora/

Things only start replicating again when I run the command service mysqld restart on slave

master my.cnf

slave my.cnf

P.S I HAVE JUST ADDED "bind-address" in both of these cnf to check if it works