I'm pretty sure this is DNS related. I have been seeing the same thing. When my own Mac is on the corporate network the device name matches the computer name. If I am using VPN, I could wind up with a windows system (previous user of ip address), when I am at home, the name is what is assigned by my cable modem (ex. new-host-4). I show both columns in the console so I'd be sure of my Macs (when listed with other OS's).