Sorry mate, it's one of the few things I can't do much about... There are so many things that affect the speed you get it's about impossible for anybody to guarantee anything. They did find out that a lot of the noise on a line (and more noise = lower speed) can be caused from within the home. To help eliminate some of the noise, you can get fit different faceplates to your fit to your wall outlets that better insulates them from the general RF noise in your house, it's supposed to help, but "mileage varies" as they say... See here;
http://www.shop.bt.c...rator-58LT.html
Also, for anybody else reading, this isn't BT specific - anybody using an internet connection that is essentially based on a phone line, can potentially benefit from this.
cheers, yeah I have my router going straight to the master socket.
BT have done better than my previous which was Orange on about 100-200KBS and they kept throttling me