Hi!
I just checked your entry and I'm a little confused. Are you saying that your MCE system isn't your DHCP server, or that it isn't on 192.168.80.1? As far as I know, that is unsupported and likely to cause some of the Dev's to wask their hands of you and tell you to stop over-thinking it
MCE NEEDS to be the DHCP server as that is how it works out what the various devices are and keeps an internal record of what is there.
Changing it's address, I can't think of a reason
not to do this (I'm guessing someone will come up with one) but I also can't think of a reason why you want want to either! It's unlikely that your home will be large enough to require more devices than can be accommodated on a Class-C network (BIG house with more than 252 devices!!!!) and 192.168.80.0 is not likely to interfere with your external network either (most routers that I've seen use 192.168.1.0)
Just my 10 Eurocents