Apologies if there are no updates in the next few days: my landline is down for the tenth time in five years. Normal service will be resumed as soon as BT can be bothered to sort it out.
Update: After eight phone calls last night and today, I finally managed to convince some chap in India who was reading from a script and who kept calling me Mr Richard that one fault every six months really shouldn't be seen as perfectly normal. The bad news is that BT have narrowed the problem down to a box of wires buried underneath the road outside the house, and they're going to have to get some temporary traffic lights set up and our neighbours to move their cars before they can sort it out. The good news is that my landline seems to be working semi-OK at the moment, but I'll be damned if I'm going to tell them that.