OscP5 not receiving messages. Processing 3.0.2, OS X 10.10.5

Hi, I'm trying to have two way conversation with pure data. I can send messages no problem but processing doesn't seem to be receiving them.

I tried running the oscP5sendReceive sketch from examples and I just get the oscP5 startup messages

[2016/3/14 0:21:36] PROCESS @ OscP5 stopped.

[2016/3/14 0:21:37] PROCESS @ UdpClient.openSocket udp socket initialized.

[2016/3/14 0:21:38] PROCESS @ UdpServer.start() new Unicast DatagramSocket created @ port 12000

[2016/3/14 0:21:38] PROCESS @ UdpServer.run() UdpServer is running @ 12000

[2016/3/14 0:21:38] INFO @ OscP5 is running. you (192.168.3.1) are listening @ port 12000

and then nothing. The sketch is definitely looping away fine, I ran it again with a print message in draw() and that gets written out at every call to draw().

Any thoughts? Is this working for anyone else with the same setup?

Thanks, Ciaran