[cups.general] Network printer changes IP address

[John Jason Jordan]

I have a Xerox Phaser 7400DN on a network and I print to it from
various applications in Ubuntu Gutsy x86_64. When I first got it the IP
address was set at the factory to 192.168.1.100. My network subnet is
0, and 100 was already used by another device, so I changed it to
192.168.0.101 via the printer's control panel. Then I set the address
in CUPS to 192.168.0.101 and all was well. 

That is, all was well until the next time I turned on the printer. I
couldn't send it any print jobs. Using the New Printer utility in CUPS
I told it to search for printers. CUPS searched the network and found
the printer, but it was now 192.168.0.102. Rather than get up and go
into the room where the Phaser 7400DN was located to change it back to
100, I just changed the address in CUPS to 192.168.0.102. 

That worked OK until the next time I turned on the printer. Repeat the
above story, except this time the printer was at 192.168.0.103. Again I
changed the address in CUPS to 192.168.0.103 and all was well. 

Today I turned on the printer again and got the same problem. Asking
CUPS to search for printers this time the address is 192.168.0.189.
Again I changed the address in CUPS to 192.168.0.189, and all was well.

The problem is that this is nuts and time consuming. I also have half a
dozen other networked printers (all HP Laserjets, of various vintages)
and they never change their IP address. 

Does anyone know what is going on?