IP Profile Good....Line speed appalling?

[#1]

Have had a constant line speed of between 2500-5000kbps for the last few years.  On Saturday morning I noticed it vvvvery slow, performing a line test showed that although the IP Profile and achievable line speed was over 4000kbps the actual speed being achieved was under 100kbps.

I tried switching over to a wired Router which Ive stayed with for the last 5 days (was using wireless BT Home Hub before). This has even improved the line IP Profile to 5000kbps, but the rate achieved is still abysmal now at 97kbps.
Ive switched routers.
Tried 3 computers.
Tried different cables.
Tried different filters.
turned off computers and routers etc etc
Nothing appears to have worked and even now the download speed is 97kbps with upload speed being 300kbps so hasnt budged in 5 days.
Anyone have any suggestions as to what may be causing this? The line is pretty stable, even increasing the IP profile. Nothing has changed my end to cause this so completely baffled.  Problem at BT exchange?Problem at Plusnets end?..... something seems to be throttling the line speed big time as everything else points to what should be my usual speed of 3 or 4mb

Although the people I have spoken to on the phone at Plusnet have tried to help they obviously have a varying degree of knowledge on this subject so couldnt offer an explanation except that it will probably increase in time. It hasnt and now Im told to raise a ticket on the matter which seems a bit of a waste of time telling me now and not 5 days ago.
Really fed up with it as its almost unusable at this speed so even checking email is hardly worth the bother.

[#2]

Ok, well the first thing we need to know mate, is if you are using a wired or wireless connection?
When I bought a new plasma tv last year, every time I switched it on, it interfeared with the wireless in my house, and I was getting less speed than on dial up, even though my router was synched at 19meg.
The solution?
Move my router as far from the tv as possible, it solved the problem.

[#3]

I was using a wireless router before without problem. I have since the weekend connected using a wired router but has made no difference (although it has improved the IP Profile to 5mb)
Exactly the same problems with both. I can understand if I had a new piece of equipment like a TV as you say, but the speed was fine Friday night then Saturday morning it was as it is now, so nothing had changed within my house during the night.

[#4]

HI markirv,
Have a look here for some tips and if that doesn't help then raise a fault.
Jojo

[#5]

Thanks, raised a fault yesterday.
Depressingly slow still today....there must be a fault somewhere with BT.


DSL Connection 5700 kbps
IP Profile 5000 kbps
Actual Download speed 170 kbps ...Upload 300 kbps

No line drops in 24 hours, clear line. Incredibly frustrating to say the least.
How long before I hear from someone dealing with the raised fault?  as this was put in yesterday evening.

[#6]

What's the Current line speed shown here?
If Plusnet haven't received or acted on a Delta report from BT, it may be set too low. The DCT can update it manually, although it usually updates itself with 12-24 hours of the BT profile changing.