In my case I was converting to a new router box and didn't quite have it 
ready when the installer came. To make things easy I put the NIC I was going 
to connect to the cable modem in a dual boot box and brought up Windows. He 
did his thing and later that afternoon I did mine. I put the card into the 
old PB P60 that was my "new" router/masq box and they don't care its the same 
MAC on the other end of the wire.

-- 
Jack Ungerleider
The Ungerleider Group - Creative Solutions for Cooperative Computing
jack at jacku.com