WIZnet WIZ550io

Have given up on the CC3000 for now, just cannot get it to behave nicely for a decent extended period. Received a WIZ550io today and am running against the 1.61 Wiznet build.

Basically working, but I cannot get eth.setIP() to DHCP nicely ..
I see ..

>eth.setIP()
> Send DHCP_DISCOVER
> Send DHCP_DISCOVER
> Send DHCP_DISCOVER
> Send DHCP_DISCOVER
> => DHCP Timeout occurred
WARNING: DHCP failed
=false
> 

After this, I see ..

>eth.getIP()
={
      "ip":"0.0.0.0",
      "subnet":"0.0.0.0",
      "gateway":"0.0.0.0",
      "dns":"0.0.0.0",
      "mac":"000000000000"
    }
> 

I am 100% sure my DHCP is working, so am a bit lost. Resetting the board and executing the following code works fine ..

var eth = require("WIZnet").connect();
eth.setIP({ ip : "192.168.254.148" });
eth.setIP({ dns : "208.67.222.222" });
eth.setIP({ gateway: "192.168.254.100" });

and I then see

>eth.getIP()
={
      "ip":"192.168.254.148",
      "subnet":"255.255.255.0",
      "gateway":"192.168.254.100",
      "dns":"208.67.222.222",
      "mac":"0008dc1d4c33"
    }
> 

So my question is, where could the problem be ?

ARP -A on my (sorry, um, Windows) PC shows ..

192.168.254.148 00-08-dc-1d-4c-33 dynamic

So that mac address is being seen, but those DHCP_DISCOVER requests are not working for reasons I don't follow yet.

TIA!