PING vanessacarlton.com (64.45.25.51): 56 data bytes
--- vanessacarlton.com ping statistics ---
10 packets transmitted, 0 packets received, 100% packet loss
Looks like the server, is down, not just IIS. Most likely, it is the host transition. A better way to do this would to keep the current server running, but start setting a short DNS expire time a few days before. Then, they put the new server up and change the DNS. Then, they take the board down on both servers (This board is down for... yada yada yada....) while they transfer the DB to the new server.