We've not got another engineer appointment booked. The trouble I think is that BT isn't looking at this as a whole. They checked today when the line was in it's failed state, confirmed no PPP session established or even trying to establish, confirmed that clearing a session on other ports immediately reconnects. From that they conclude it must be at my end. Concluding "I would say the fact we are receiving no PPP requests from this EU is contributed to the poor quality copper line and resetting the CPE/ port temporarily resolves this as the ADSL sync re-trains"
I think it's got A&A at a bit of a loss as well. However we'll see what comes of the engineer visit. Next stage might be another change of CPE, A&A are suggesting trying a D-Link modem. Although not sure what that proves, if it works OK have we just proved that a couple of months ago the line became incompatible with anything except D-Link?