I am not sure if you changed anything your side, but the problem has cleared up for me now
I changed all my CPE equipment over except the modem, new shielded wiring from the point, new faceplate for the phone jack, new adsl filter.
I also bought a new modem and signed up with a tier-1 service provider, however I have not been cut across to them as of yet. (Hopefully this week coming)
Never the less, the problem is no longer with me at this point, so I am very happy and if it was a fix on your end then it is very much appreciated