Ok so your hosting lobbies and then your banned, but wait dont go on your regular console you can still host for another hour or so.
Here's what to do:
1.Host lobbies until KV is banned
2.Unplug your power cable
2.Wait ten seconds and put it back in
3.Boot it back up and quickly start a MW2 system link lobby.
4.While the lobby is loading connect to XBOX LIVE and you should be set to host for another 30-60 mins