Confused about why I'm getting slow speed .. (and further confused by support!)

[#1]

Wonder if anyone can explain what is occurring with my connection - my line appears to be syncing at a good speed (@7400 - 7500 kbps reported by router) but I am getting only @1600 on any broadband tests... I have tried to eliminate the possibility of any equipment fault within the house by doing the following:
- plugging into master socket
- unplugging other phone equipment
- plugging brand new short cat 5e cable into modem and laptop and testing from there (same results)
Is it the case that my line is not constantly syncing at this so I am throttled down to a lower speed connection for stability due to MaxDSL being rate adaptive (in which case it would be useful if support had stated this in their answers to me!) or does the problem lie elsewhere?  Is there anything I can do?
Have shown various equipment info below along with some of the correspondance with support - any help welcome...
 

first some equipment info and then some info from support
(call ID: 27873936)
Router Netgear DG834 v2 - stats from today
ADSL Firmware Version 1.00.09.00
Normal faceplate socket
ADSL Link Downstream Upstream
Connection Speed 7552 kbps 448 kbps
Line Attenuation 37 db 20.5 db
Noise Margin 5 db 25 db
Master socket
ADSL Link Downstream Upstream
Connection Speed 7424 kbps 448 kbps
Line Attenuation 37 db 20.5 db
Noise Margin 6 db 25 db

Connected support on Saturday to ask why my speeds were registering at @ 1600 kbps on various broadband checkers
(including BTs) when modem was reporting downstream of approx 7500 kbps.  Support replied:
"I have checked your line today and can confirm that you are now syncing at a very good rate. Your speeds will be
automatically updated at your local exchange when you have managed at least 72 hours without a drop in connection."
Modem left on and not to my knowledge powered off at any point since then...
Asked support to clarify why I was seeing @ 7500 kbps at modem but only @ 1600 at PC - and asked was there anything
I needed to tweak or change at the PC end.
Support replied:
"Once the line is stable for 72 hours then the throughput speed will also be updated.
This is done after because if the line is unstable, then the higher speed simply will not work."
Supplied BT results and asked again why speed at PC and at modem different and asked why service not upgraded since my exchange had been capable of high speeds (apparently!) since 2006 and recieved the following response from support:
"Further testing can not see any faults with your line. Your current line rate is 2000 therefore you will not see speeds any faster than this. MaxDSL is a rate adaptive service where the speed will reduce in order for connectivity to remain more stable if there are higher levels of noise on the line. In order to improve your line profile you have to remain synchronized at a higher speed for 3 consecutive days. In this time just one instance of a lower sync will mean you stay at the lower speed and the 3 day count will begin again.
Our line tests show no fault with the physical copper line itself, therefore it is likely the noise is being generated by your internal wiring or equipment.
Please test again your connection monitoring the sync speeds you see on the modem/router. If you still see low sync instances and still feel the fault is outside your control then please get back to us and we will raise the fault to BT. Please be aware that should BT find no fault with the line itself then they may charge you an abortive charge of £144+VAT. If the line is perfect from here you will need to go through your internal wiring and equipment checking for interference." 

[#2]

Can you post the results from the BT speedtest please.

[#3]

BT speedtest showing:
Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 7424 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 1587 kbps
If you wish to discuss these results please contact your ISP.

[#4]

Current Profiled speed on Plusnet network (from Plusnet info page)
Estimated line speed:
Not recorded (service activated before we introduced estimates).
Current line speed:
1750

[#5]

Well you need someone in PN to fix that to match the BT speed! 

[#6]

Hmm.. that's what I was thinking too but support haven't been very forthcoming   Have suggested that to them now.....  awaiting response....
adie:quote

[#7]

An earlier response from support quoted "your current line rate is 2000". It's not clear where this figure came from, but the question remains what happened to cause your sync speed to drop and give you a profile of 1750.
Did you accidentally plug anything in without a filter? Otherwise, there may be a lot of interference, or perhaps a bad connection. Can you hear any crackling or other intermittent noises on your line?

[#8]

Hiya,
The speed profile at our end had been updated to match BTs before I could get to your account.
Can you try rebooting and see if you notice an improvement?

[#9]

Thanks for replies
Anotherone - no noise on phone line, no faulty equipment, no unfileterd lines - in fact the only thing plugged in at the moment is my router  which is plugged into the test socket in the master socket - although results are the same as peviously when it was plugged into faceplate part of socket with one connected (filtered) phone...!
JamesH - I was hoping that may happen (ie profile being matched to the BT one...) - am at work atm but will check and reboot router if neccessary as soo as I get home.... However support have now added to my ticket that I need to go through the broadband fault finding wizard ... do I need to do that?

[#10]

Not if your speeds have improved

[#11]

Hmmm... all initially looked ok last night but now it's not so good  - see below.  Any suggestions JamesH - or anyone else?
BT speedtest @18:00 18/02/09:
Your DSL connection rate: 7584 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 5620 kbps
Around 23:30 18/02/09:

Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 7424 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 437 kbps
And tonight @ 21:00 it was:
Test1
  Your DSL connection rate: 7584 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 279 kbps
advised to carry out further test as bt_test_user@plusdsl.net
Test2
Your DSL connection rate: 7584 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 3177 kbps
Your service was found to be performing poorly. Please raise a fault with your service provider, stating that the BT
Performance Tester tool indicates poor service throughput performance after the first test.
Any suggestions JamesH?? (or anyone else!)

[#12]

when you get a bad throughput result on the bt test site can you go straight to your PN member centre and use the mybroadband speed checker.
as your getting decent speeds and then a low 3 figure one from bt i would just like to see what the member centre speed checker results are soon after bt gives you a poor result.
i find the bt site does that alot and in past i have sat with 2 other speed checker sites booted up and ready to go as soon as bt gives me the result and when bt gives a 3 figure result the other two speed checker site straight after come back at my normal 2300-2400 througput range.
sum's it up really wouldnt surrpise me those poor results are what BT have planed as the norm for pn's network.