ADSL Max problem

[#1]

Hi,
I have had a problem with my connection for a while now, I was hoping I would not have to investigate it, but it has got very much worse. Currently my Rx Noise is some sort of negative number, my Router connection speed is 6752 kpbs, but since I have more noise than signal my throughput is low and has been for several days, below is the result of a recent BT speed test:
Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 6752 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 5500 kbps
    Actual IP throughput achieved during the test was - 1092 kbps.
Clearly I need to start testing at the Maser socket, this will cause a number of restarts. I am on an ADSL MAX connection so I suspect that the  restarts will alter my connection speed and cloud the results of my testing. Am I correct in thinking this? If I am how do I work out what is happening?

[#2]

As long as you dont drop the connection several times in quick succession you should be ok. If you plug into the master socket there is no reason to restart a lot you need to give it time to test.
If you need to restart turn it off for 5 mins and you should be ok my understanding is it only effects it if you drop the line if you disconnect for 5 mins this should be normal

[#3]

It used to be that up to 10 resync's per hour would not cause the BT exchange to increase the SNR in an attempt to stabilise your line, but I have seen it kicking in with as few as 3-4 resync's in quick succession.
It is better if you login into your router's control panel and select disconnect from there, before you power down the router.  Then you can disconnect the telephone wire and what have you.  Do this every time and also as samuria says wait for 10 minutes or so before you power up again.  In this fashion your connection speeds should not be affected by the exchange - I know because I had to do exactly the same thing yesterday when I was testing a new router.

[#4]

Mine did just that yesterday and now I am back at 15dB 
Thank God for DMT

[#5]

I believe that it's multiple resyncs within 15 minutes.

[#6]

Thanks everyone for the useful replies.
Now of course I have more questions. My ADSL connection is though a modified NTE5 faceplate, form which I run the POTS and distribute the ADSL signal to my modem. To isolate the fault I have removed the faceplate and inserted a separate micro-filter into the Master Socket. The Modem is thus plugged directly into the Master Socket and all other extensions removed. I am connecting to the Router over a wireless link.
Below is my latest BT test:
Test1 comprises of Best Effort Test: -provides background information.
Your DSL connection rate: 7008 kbps(DOWN-STREAM), 448 kbps(UP-STREAM)
IP profile for your line is - 6000 kbps
Actual IP throughput achieved during the test was - 3182 kbps
My Downstream noise margin is 15db.
My system had been running like this for around 139 hours. I had expected that my Noise Margin would improve, but it has remained for all this time at 15db. Should my noise margin have improved? I am trying to get a measure of the state of my line before I undertake any further testing, it look as though my problems are internal but I would like to see what my line is capable of at its best.

[#7]

Your line is pretty close to maximum speed. With BT's "new" logic any adjustment is likely to be very slow and small.
If you're getting over 7meg at 15dB a small change to a 12dB profile would almost certainly get you 8meg (or slightly less if interleaved) and the margin would just show as whatever it was at the limit, probably between 12 and 15dB.
Of course you profile could be "stuck" but you wouldn't know that until waiting for a couple of weeks or more....
First thing I'd do is check interleaving status and turn it off (Fastpath) if it's on.