Update...

I did manage to get the Vista (Jands console) to talk to PixelMAD directly but I had to cheat to do it: Firstly I put a Windows laptop on the network with the DMX workshop software from Artistic Licence and managed to get to pretend to be a port and got the Vista console to talk to that. Then I set the PixelMad Mac to have the same IP as the Windows computer and swapped them over. The PixelMAD system will not recognise the Vista (or Artistic software) as a valid Artnet device but it is showing data in the DMX window and it works!!

It would seem that the PixelMAD is not responding to a Poll from a console. I understand that as Server it used to be optional, however Wayne at Artistic tells me that it is now a mandatory part of the recently revised protocol specifically to address this situation when something is a combined server and node.