Download speed awful, line speed excellent. Eh?

[#1]

For the last two days I've been seeing an effective download speed of around 1000kbps, but my router is connected at 8128kbps.
I usually see figures around 6-7000kbps on the Plusnet speed test page but something has changed.
It feels like all my traffic is being shaped/throttled... surely I'm not seeing sudden unprecedented contention 24 hours per day? I even AVG scanned my PC. No discernible network traffic is seen between PC and router. Mmm.
Video is full of stutters. 
Any help, folks?
Peter

[#2]

I'm on "PlusNet Broadband Your Way Option 3 with included 30GB bandwidth".
I attach screenshots of PN and BT speedtests.
Pete.

[#3]

Hi Dizzley,
I've tested the line and can't see any problems either at the exchange or on our servers here, the profile matches across the exchange kit. I suspect the best thing to do would be to raise a fault to be honest - if you go through the wizard at http://faults.plus.net we'll get it investigated for you.

[#4]

I've found the problem.
Thanks Matt for testing.
Err... someone (that would be me) copied 4GB of data from a thumb drive onto the PC and someone (that would be me) has an automatic rsync backup running which had picked it up and was uploading it daily.
I discovered what was doing the naughty using TCPView from Sysinternals.
Speed is now showing at 7012kbps download.
D'Oh!  
Hehe,
Pete.

[#5]

Thanks for letting us know Dizzley, glad you got that one sussed!