Can my IP profile be increased quickly?

[#1]

Sorry, had lost track of the fact you'd got a ticket open (if you'd mentioned it somewhere else), what did you say, what reply have you got?
I'd guess an interim response along the lines of "things seem slightly improved, I'll continue to monitor for a while".
When you have time, post the latest RouterStats NoiseMargin graph. (Did you have any luck with screws?)

[#2]

I raised a ticket via the broadband faults tool when my sync rate had declined to below 2000Kbps (See thread http://community.plus.net/forum/index.php/topic,76008.0.html).
There is quite a lot on the ticket but to summerise they could not find a fault but noted that the sync speed was slower than expected.
I got a long reply with all the obvious things to try and then an offer of a large bill from BT.
I haven't replied since I discovered the problem with the cable.  I'm not at home much but I will post a graph ASAP.  (I haven't had time to visit a shop so the screw is still missing.)

[#3]

Here's the SNRM graph:

[#4]

Hmm, still not nice, keeping listening to the phone line periodically. The reason I asked who you paid line rental to and what phone package it was (you didn't say), was because it should include some free/inclusive calls and if you were to use it more often there would be a greater chance of you hearing any crackling or other intermittent noises, if that's the cause.
That said it's also worth looking at the possibility of electrical interference. Go round and switch off all electical appliances in turn, all energy saving lamps, fluorescents, including the transformer for halogen lights, power packs for anything (other than the router!) even your monitor and watch the noise plot and see if that variation stops.
HTH.

[#5]

We're on BT's cheapest package.  I can't remember what it's called    I've not noticed any particular noises on the line during calls or with the quiet line test.
I've tried turning things off as you suggested, but it did not make any difference.

[#6]

It's unfortunate in this situation, that you just have to keep investigating,  think about other possible causes, check them out etc. It could be a close neighbours equipment causing problems. Monitor continuously over the next 24-36 hrs and see if the graphs are worse at any specific times. Post a selection of graphs from daytime and night-time.

[#7]

Thanks again, Anotherone, for your continuing help.
I am out of ideas on other possible causes.  Every time I have a theory and test it, it proves to be wrong.  If it is close neighbours causing the problems then I don't know how I could do anything about it.
I have attached some of the more recent graphs.  I haven't got any daytime graphs because I am not in during the day.  Note that the disconnection on the 11th is my fault and can be ignored.

[#8]

Trying to discover whether this is electrical interference or a line problem could be tedious. What is strange is things stayed relatively flat until the evening of May 12th. Are they still noisy?

[#9]

The SNRM variation after May 12th is more typical of what I have seen in the past.  Here is a graph from today which shows the same kind of pattern.  I will probably try my other router again tomorrow and see if this makes any difference.  I could also run routerstats lite from another PC, leaving my PC switched off in case it is this.

[#10]

That might be an idea, it has been known for PC power supplies to cause problems. Don't forget to try with your monitor off if you haven't already. Set Router Stats running, if it's showing noise, then unplug the mains to the monitor for half an hour, then plug the monitor in again and see what happened.

[#11]

Turning off the monitor did not make any difference.  I'll try the PC later.

[#12]

Turning off my PC did not make any difference either.

[#13]

Hmm. Keep thinking
I know this will be tedious. irritating etc, as you'll no doubt have to reset any electric clocks and the like, but turn of as many circuits as you can at your main distribution board, obviously you'll have to keep the power on to the sockets your router is on, but try unplugging/switching off everything else. See if you can find any difference.
If that's what you've already done, then were are down to a line problem or REIN/RFI neither of which will be especially easy to nail down under present circumstances (on the assumption you tried one of your other modem/routers again and the problem is still there).

[#14]

Thanks. I'll try this ASAP, but it may not be until the weekend.  Most of the sockets are on the same circuit, however.