'Networking' admin panel crashed. Was it my fault?

[Chanchao]

I couldn't get into my Networking panel anymore to change networking
settings.  Even before the screen opens, a bug reporting tool opens.

Tracing back what I did the evening prior, I found it was the result of
me installing Samba as a domain controller as per the instructions here:

http://www.howtoforge.com/samba_setup_ubuntu_5.10

As part of that, it told me to enter the other PC's on my network in
the /etc/host file.  Now I'm just testing this PDC setup on my laptop,
and being a laptop I am on different networks all the time.

So is it wrong to define a bunch of hosts in the host file that aren't
always reachable/valid on the network I'm connected to?  The offending
host file looked like this:

-----
127.0.0.1 localhost chan-laptop
127.0.1.1 chan-laptop
172.16.10.15 exchange

192.168.1.50 uan
192.168.1.51 fdg-server
192.168.1.52 demo

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
----------------

Note the bunch of 192.168.1.* hosts, those are the ones on my home
network.  Normally I'm set up as being on 172.16.10.* which is my
company network.   I actually have a host mapped for it, the
172.16.10.15 'exchange' one. 

I do note that the Networking admin panel doesn't throw a tantrum
because of that entry when I'm on the 192.168.1.* range at home.  

So why does it object to those 3 entries?  Or is it really a bug in
network-admin ?

Cheers,
Chanchao