So... now I have got home and had the chance to play...

I've changed the modem cable and rebooted and bang :

ADSL Link                   Downstream      Upstream      
Connection Speed        13237 kbps        1033 kbps
Line Attenuation           19.5 db              10.5 db
Noise Margin                12.0 db              13.0 db

So pretty happy with that! Given my old house had downstream attenuation up around 50db and I was lucky to get 2mbps - this is much better!