I originally posted here a question about why when my digibox was plugged into the mains my internet connection was much slower than when the digibox was not plugged into the mains. I phoned a friendly retired BT engineer & he had an answer. The connections in the back of the main BT phone socket - the first in the house - had come loose. The phones worked normally but the problem showed itself on the internet connection speed. Connections tightened & problem gone. The difference is 49333 with good connection & 33000 without. Might just help someone.