Although not a direct answer to your question, it will bump your posting back to the top so others might respond.
I have just moved from Norfolk to Suffolk - about 10 miles. Whilst in Norfolk, I had 4 lines going into my home and these were installed from scratch within 2 weeks. However, in my new home, I waited 2 months for BT to upgrade an existing line to ADSL and am still waiting for a second line to be put into my office at home. I was told that 'capacity' issues have created this delay and am still waiting for trunking [completed 2 weeks ago] and new cabling for my second line. I am not REALLY in the sticks - I live just outside a relatively large town - and there will be about 800 homes built over the next few years on land joining the back of my property. Perhaps, based on my experience, there ARE limited capacity for ADSL and additional phone lines, depending on where you live.
Interestingly, AOL managed to upgrade my private phone line to Broadband within 3 days ....