Interactive does work in Brighton, so I would just reboot your box (unplug it from the mains for 10 seconds) and then try again. You should find this works whenever you get error messages like that.
If that fails to work, then you should call Customer Services.
And just for your information, ntl does not carry any form of interactive service on any of the Sky channels, so forget about pressing red on Sky News.
Browneggsandham