Shame that no one has taken this up!
In case more info might generate some interest, here's some more detail.
Even though the old machine was removed nearly three weeks now, it shows twice. The first is with an icon, IP 192.168.1.104, part MAC 00-03, the other with a ?, IP 192.168.1.107, part MAC 2C-08. I'm guessing that one of those might relate to some s/ware I installed to aid the movement of recordings from the old to new PVR.
Anyways as any reference to the old is not needed, because it no longer exists, how do I zap it?