Hi MicroMatt
good to here there has been some progress. Its all to much of a coincidence but my connection seems to have setled down and my upstream level has gone from a fluctuating 50 to 61dbmv to a steady 40 dbmv at the moment.Also the unicast maint ranging has stopped giving error messages in the modem log. From the NTL service page there is work going on in the Guildford area. Lets hope it stays working,at least I got a new modem out of it.
http://www.ntl-isp.ntl.com/ServiceStatus/
chrisntl