Thanks Kitz,
I have installed an ADSL nation filtered faceplate to the master socket, connected via one of their pro cables, relocated the router away from other equipment, power supplies etc and I am still getting LOS errors. I cannot match the timing of these to any household electrical event ie lights, heating, tv etc so I can only assume that the noise issues I have are external.
I nearly had interleave switched off the other day and would have if they did what you asked them to in an email! I eventually gave up after the 2nd e-mail I sent was bounced back with a "if you really, really, really want interleave switched off then contact us again" response! I guess you have to ask them 3 times really, really, really nicely!
So this is the end for me! I have spent way too much time on this already and I have a much better connection than an awful lot of people.
Thanks to everyone on this forum for helping me to understand the wonders ADSL MAX!
Tony