
to Cable Forum
With the cable network the IP addy you get is not static. It can change for all sorts of reasons, your own modem/stb refreshes it's connection, something on the network is rebooted or reconfigured. It can stay the same for months, or change frequently. Dynamic IP addresses is why banning access to users on forums and the like is often a waste of time.
As for the packet loos / poor performance maybe there has been some sort of network reconfiguration (which explains the new IP) but you are the looser.