Recent loss of upstream sync rate Possible Fault?

Hello. Randomly last week i saw my router resync at somepoint during the day and the upstream was no longer at its normal 700kb/s .

Now for the past 3-4 days its been stuck at 384kb/s

Connection Speed 1472 kbps 384 kbps
Line Attenuation 63.5 db 31.0 db
Noise Margin 6.8 db 8.0 db

Im on ADSL Max Business product with vivaciti.net
I have tried 2 routers 2wire/netgear Same result.
Im plugged into a Faceplate fitted by bt so dont have filters.

IS this a line fault?

Forgot to say the Upstream does "improve" on the 2wire (500kb/s) but normaly it syncs at near 800.