Speed drop

[#1]

Sometime during Tuesday night my speed dropped from around 940k to 250k and hasn't improved, infact my upload is faster than my download.
There hasn't been any change in equipment at home, nor have I hit my maximum usage allowance.
Computer checked for virii and adware - clean.
Current line speed: 1Mb
BT Speedtester
Download speed achieved during the test was - 421 Kbps
For your connection, the acceptable range of speeds is 200-1000 Kbps.
Additional Information:
Your DSL Connection Rate :1440 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 1000 Kbps
Router Information
Plusnet provided Thomson router.
Uptime: 1 day, 1:15:02
DSL Type: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,440
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 12.0 / 16.0
Line Attenuation (Up/Down) [dB]: 31.5 / 63.5
SN Margin (Up/Down) [dB]: 11.0 / 11.0
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 22 / 0
FEC Errors (Up/Down): 55 / 166,158
CRC Errors (Up/Down): 55 / 946
HEC Errors (Up/Down): 26 / 690

[#2]

Have you tried re-booting browser, computer or power cycling router ?
http://community.plus.net/forum/index.php/topic,99435.msg844488.html#msg844488
Re-booting browser cleared my massive drop in speed

[#3]

@MrZeno,
I've checked your account and can't see an obvious reason for the drop in speed.
Try rebooting and if that doesn't help things try logging a fault here: https://portal.plus.net/apps/kbdfaults

[#4]

@PlusComUK - Thanks for the advice but it's not FF as it is the same in IE and Chrome.
I rebooted the router the same day the problem started, no improvement.

@_Adam_Walker_
I've just rerun the BT speedtest with the following result:
Download speedachieved during the test was - 79 Kbps
For your connection, the acceptable range of speeds is 200-1000 Kbps.
Additional Information:
Your DSL Connection Rate :1440 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 1000 Kbps

I also managed to get the third test to work with the following result:
Download speedachieved during the test was - 86 Kbps
For your connection, the acceptable range of speeds is 200-1000 Kbps.
IP Profile for your line is - 1000 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 third test.
I've been trying to reconnect to the internet since running that test and kept getting "Could not bring up link", it eventually worked as I'm posting this.
Thanks

[#5]

Hi there, I can see you've started raising a fault - definitely the best thing to do with this one. If you could go back and finish answering the questions we'll get it investigated and raised for you.

[#6]

Finished off the fault reporting, just needed to try a different router before continuing.
Thank you for your help.
Jason