[Xaccers]

I think you underestimate the tracking powers of debt collectors (my mate used to work for one)

I also have been in the position of recieving debt collectors letters for people who have lived with me. They were eventually tracked down.

They have paid NTL for the debt. NTL no longer care.
You have this agency who's sole purpose is to track people like you down and make you pay.
You now owe them the money.

If you are buying a new house, they can go through the estate agent.