Bzzzz ... slow broadband!

[#1]

I changed absolutely nothing. Mand changed my settings from 250 to 4000 for me though. I rebooted the router once.
Is that a good or a bad thing having lower numbers?

[#2]

Hmmm, just had two wobbles in my line and it has dropped my sync speed and noise margin slightly (ignore all the other drops with red bits in them - they are from when I accessed my router or rebooted it).

[#3]

Attenuation as low as yours (whether it's 4 or even 10) is something many of us can only dream about.
You clearly had some stability problems around 12.20 today (shown by the noise margin graph), resulting in resyncs and drops in connection speed. Is there anything inside your home that could explain this?
What's the wiring situation in your home like? Do you have a modern master socket? Can you plug directly into the test socket inside (if it's a modern one)?
See http://www.kitz.co.uk/adsl/socket.htm for details of sockets.
I don't have a modern socket, but it made a big difference to my line when I had the 'ring wire' disconnected.
Graham

[#4]

My master socket is looks very similar to the first one on the page. I don't know whether it is "modern" or not.
No, there was nothing going on in my home that could have caused this to be honest with you. I was just sitting on my couch surfing the internet. Total power usage is 0.07 kW at the moment.
Ring Wire: I am currently plugged into the test socket - would this make a difference? Only 2, 3 and 5 are currently connected.