I did disconnect the extension wiring but had Sky+ installed yesterday and was told that I need to have the Sky box connected to a telephone line so the engineer reconnected the extension wiring. My broadand speed seems to have dropped since then. I might try only connecting wires 2 + 5 but it says you have to do that with all your sockets and I have loads!
This seems to be happening a lot with Sky installations. The Sky engineers fit the equipment with no regard to your broadband and mess up the connection in the process.
You might be lucky and he may have just upset your profile, if this is the case your speed should pick up in 3 days but if it isn't filtered it will affect the connection until you can get it filtered.
The ADSL Nation faceplate linked to by crosstrainer is highly regarded.
I have disconnected the wiring in all the extension sockets, leaving wires 2 + 5 and I seem to be back up to 7.7Mbps. Getting slower speedtests though but that might pick up. I did order crosstrainer's suggested faceplate but not sure that I need it now.