helimutt
Some confuser forums recommend switching the router off every so often, as the max speed will reduce as the kit in the exchange works out the highest stable speed that your line can sustain. I am 6km from my local exchange, and have found it benificial to do this if the speed has dropped to a very low figure - switching off (for 30secs or so) pushes the speed back up to the line's absolute max (or so I've been told!). Works for me, anyway (allowing for the dreaded 'contention' issue, where the speed drops when all the kids come home from school and start downloadind music and videos!).