NTL suck anyway. No-one would use their service unless they had to or didn't know better. They offer a very poor service, they have a 1GB download cap, and there is a lot of downtime. Also the proxy service they offer is often as slow as hell, but you'd probably have to use it to get around their enforced proxy.
In case that's not clear enough:
AVOID NTL!!!
BT is almost as bad, but not quite. In fact, in the UK, internet is in the stone age.
I strongly recommend Telewest's Blueyonder service for anyone living in cable areas in the UK. They don't enforce proxies, there are no caps, there is no downtime, you always get your full bandwidth, you can connect with any system that supports DHCP, and they don't spam you or profit by sending your email off to all and sundry. In fact their service is almost perfect. In other words, the opposite of NTL.