Need to sudo and make this file: /etc/nsmb.conf
Additionally, on a copy of Mavericks I had to run the "sudo sysctl -w net.inet.tcp.delayed_ack=0" command. I also turned off NetBIOS queries, so my nsmb.conf file looks like this:
Additionally, to add NetBIOS names to your mac, add them like this in your nsmb.conf:
All thanks to this article on MacWindows.