Another BT problem

[Simps]

I have a strange problem.
My line is constantly loosing speed. I have to reboot the router to get my speed back.
I have tried a different router, micro filter, dsl and lan cable and the same thing happens. After rebooting the speed picks up again but after anything between 5 and 15 mins it goes again.
I thought it was my HomeHub to start with so I bought a DrayTek 2800 and still the same happens.
Has anyone got any ideas to what is causing this please...

Info....

ADSL Status Mode State. G.DMT SHOWTIME
Up Speed. 448000
Down Speed. 8128000
SNR Margin.11.5
Loop Att. 19.5

Model Name : Vigor2800 series
Firmware Version : 2.7.1
Build Date/Time : Fri Sep 22 17:7:35.84 2006
ADSL Firmware Version : E.38.2.23 Annex A

I believe that is the latest firmware also.

 

[Badger2003]

Try plugging directly into the master BT socket - this will prove wheter your internal extension cabling is causing the problem.

 

[Simps]

Try plugging directly into the master BT socket - this will prove wheter your internal extension cabling is causing the problem.

The filter is plugged directly into the main phone socket, I have no extention cables.