Slow Speeds and Line stats

[#1]

After changing the line filters in my house, there was a dramatic increase in broadband speed received so I didnt bother changing from my old modem to the new router supplied by plusnet. However, over the last week or so I have noticed my line speed has become slower and slower. I have had a few disconnections but nothing out of the ordinary. After get constant modem speeds of 1.1 meg, I decided to switch on the new router. However, even though im not getting any disconnections at all, the modem speed has reduced again.
Can anyone please advise if my router stats are really poor and is this the reason for my ip profile being constantly reduced. Also, am I going to have to put up with slow speeds from now on?
Uptime: 1 day, 4:27:03

DSL Type: G.992.5 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,151

Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00

Output Power (Up/Down) [dBm]: 12.0 / 19.0

Line Attenuation (Up/Down) [dB]: 22.0 / 40.0

SN Margin (Up/Down) [dB]: 18.5 / 22.5

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): 0 / 0

FEC Errors (Up/Down): 18 / 3,707

CRC Errors (Up/Down): 18 / 16

HEC Errors (Up/Down): 399 / 15
Can anyone explain if these are parti

[#2]

They are rotten and indicate a major problem.
Can you try the test socket behind the master socket with nothing else connected and report the stats
Are you sure that something isn't connected without a filter such as a Skybox

[#3]

OldJim,
Thanks for the quick response. i am going to have a think about what to do.
Currently, there are 2 sockets in the house, the main one downstairs and the other in the adjoined bedroom. The feed for my broadband comes from the one upstairs. Both sockets have new filters installed which led to increased speeds straightaway which I thought had resolved the problem.  I will need to purchase another RJ11 cable in order to perform a test from the test socket.

[#4]

If you are going to buy a cable then I would recommend an RJ45 network cable to go from the router (local to the test socket) to the computer.
You could also think about getting a wireless card so you don't need any cables - like this one http://www.amazon.co.uk/Edimax-EW-7128G-Wireless-802-11b-Ralink/dp/B000KLNRBS/ref=sr_1_1?ie=UTF8&s=e...