Poor Download Speed

[#1]

Hi,
I've just switched to Plusnet from another ISP. I'm on ADSL2+, Cheltenham exchange. Using the same modem as I used for my previous ISP
Initially my download speed was around 8Mb/s - it's what I would expect for my line based on what I have received from my previous two ISPs.
On 26 Feb speedtest.net gave 8.1Mb/s down 7:15am
Sometime after that, and every time I have checked since, my download speed is at the 5Mb/s level - far lower than I would expect.
I've just had my upload speed uncapped. As expected, upload has improved but it has not altered the download speed at all.
I can't see any obvious reason for this change. The ADSL sync speed is still in the 9300Kb/s range.
I'm connected via ethernet. No other devices connected at the time of testing. Modem connected to master socket. Phone correctly filtered. No extension wiring. None of this has been changed since I moved to Plusnet.
Does anyone have ideas for what I could try to identify the problem?
Thanks,
Steve.

I've run the following diagnostics this morning (06 March @ 08:25)
http://speedtest.btwholesale.com reports
Download speed achieved during the test was - 5.09 Mbps
For your connection, the acceptable range of speeds is 4 Mbps-21 Mbps.
IP Profile for your line is - 8.15 Mbps
Upload speed achieved during the test was - 0.99Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
http://usertools.plus.net/@gateway/
You are currently connected to gateway ptw-ag01.

C:\>pathping ntp.plus.net -q 50
Tracing route to ntp.plus.net [212.159.13.49]
over a maximum of 30 hops:
  0  XXXXX.Home [192.168.0.2]
  1  YYYYY.Home [192.168.0.1]
  2  lo0-central10.ptw-ag01.plus.net [195.166.128.195]
  3  link9-central10.ptw-gw01.plus.net [84.93.248.16]
  4  xe-0-2-0.ptw-cr01.plus.net [212.159.1.16]
  5  te9-4.ptn-gw01.plus.net [195.166.129.33]
  6  vl55.ptn-lb01.plus.net [212.159.2.124]
  7  cdns01.plus.net [212.159.13.49]
Computing statistics for 87 seconds...
            Source to Here  This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                          XXXXX.Home [192.168.0.2]
                                0/  50 =  0%  |
  1    0ms    0/  50 =  0%    0/  50 =  0%  YYYYY.Home [192.168.0.1]
                                0/  50 =  0%  |
  2  34ms    0/  50 =  0%    0/  50 =  0% lo0-central10.ptw-ag01.plus.net [195.166.128.195]
                                0/  50 =  0%  |
  3  15ms    0/  50 =  0%    0/  50 =  0% link9-central10.ptw-gw01.plus.net[84.93.248.16]
                                0/  50 =  0%  |
  4  20ms    0/  50 =  0%    0/  50 =  0% xe-0-2-0.ptw-cr01.plus.net [212.159.1.16]
                                0/  50 =  0%  |
  5  15ms    0/  50 =  0%    0/  50 =  0%  te9-4.ptn-gw01.plus.net [195.166.129.33]
                                0/  50 =  0%  |
  6  19ms    0/  50 =  0%    0/  50 =  0%  vl55.ptn-lb01.plus.net [212.159.2.124]
                                0/  50 =  0%  |
  7  16ms    0/  50 =  0%    0/  50 =  0%  cdns01.plus.net [212.159.13.49]
Trace complete.

[#2]

What's your Current Line Speed?

[#3]

Phone exchange:
    CHELTENHAM
Estimated line speed:
    5Mb (This may vary between 3Mb and 8Mb) - Checked on 2013-02-03 14:19:15
Current line speed:
    5.4 Mb
Steve.

[#4]

Hidden somewhere in the forum is information on this 
The "Current line speed"  Plusnet give should be (about) the same as the BTw IP Profile, but it sometimes updates late (or gets stuck) when the BT value increases. It should correct itself after a relatively short time, but if it doesn't someone from Plusnet will adjust it for you.

[#5]

Hi there,
Looks like it's been improved on the supplier system we get our reports from, it's at 8000 on there so I've upped it on ours to match - please let us know if it's not made any difference?

[#6]

Thanks Matt, download speeds are now at circa 7.5Mbps (via speedtest.net)
My BT IP Profile has gone up again, after I switched a cable my end. It is now
IP Profile for your line is - 8.87 Mbps
will (should) the plusnet systems automatically detect this and lift the Current Line Speed that your systems are using?
Thanks for your help
Steve.

[#7]

Quote

will (should) the plusnet systems automatically detect this and lift the Current Line Speed that your systems are using

They should but it I've just updated it anyway for you.