convert a server to a desktop... what happened?

[Patrick Doyle]

I decided I wanted a user interface on my Ubuntu 9.10 server, so I
naively tried the following:

$ sudo tasksel install ubuntu-desktop

and, because I don't like middle-of-the-night-after-a-power-failure
surprises, I rebooted the machine once that completed.

Much to my surprise, the machine now has a new IP address, despite the
fact that /etc/network/interfaces says:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
     address a.b.c.d
     netmask 255.255.0.0
     gateway a.b.0.1

Does anybody have any idea what just happened here?

--wpd