Repetitive daily loss of sync (Possibly Now Resolved)

[#1]

@nanotm - you're going to have to help me out here as I could be mis-reading your post.
Please remember that my DSL connection was fine for 23 hours and 55 minutes each day. It was only during a 5 minute period in the evening that there was a double resync followed by a reduction in sync rate and an increase in SNR margin.
For a current to flow in a circuit, the circuit must be continuous. So, both ends of my "split pair" must have been terminated.
If my line was being moved between DSL cards, this surely would not have happened on about 5 evenings a week over a period of 6 weeks.

[#2]

ahh,
no it would of been a sympathetic circuit, one end was terminated (your end) the other end would of had a single side terminated and then it would of had induced current flow in the unattached wire that was terminated at the exchange (but not at your end)
its not a common problem and the time between re-syncs would suggest that at some point something caused a disruption (something caused interference signal) to that sympathetic circuit, probably something electrical operating on a timer at some point between your property and the exchange (literally anywhere along the path of the line) 
and the incorrect wiring only came to light after they moved the circuit and the person doing it would of connected the tagged pair (as would be normal) rather than tagging both sides of the split pair wire.
its rather hard to explain without going into full on electromagnetic transmission and propagation theory of low level circuits (which is what stops microchips from being developed in smaller die's without being able to accurately deliver pico volts from the motherboard) but essentially you must have been extremely lucky in the conditions of your line to have only had 1 trouble spot in a 24hour period

[#3]

I've read somewhere that the BTOR report to PN gets appended to my fault ticket.
I look forward to reading what they say on the subject - presumably this will only say what they actually did and will not necessarily explain what caused the problem in the first place!

[#4]

not sure if that means your able to read it,
when I had a fault there was nothing added to the system that I could read, I would also say that unless the engineer did some pretty high end testing its highly unlikely he would of found anything, its far more likely he plugged a TDR into the circuit and saw there was a break in the connection at the drop wire point on half of the pair which lead to the diagnosis of a split pair and its unlikely he would of done anything more unless he was a very conscientious linesman with no more jobs on his call out card for the day

[#5]

The Engineer identified the "split pair" simply by the colour of the legs connected to the master socket.

[#6]

Hi MrT,
Just updated your profile for you, our side now matches that at BTs (4300) - hope that improves things for you. Given your connection has now been stable for over 4 days things are looking very good indeed

[#7]

Great, thanks Matt.
I've just run a speed test and all's well.