orange to 3 and white/orange to 4
green to 2 and white/green to 5
blue to 1 and white/blue to 6
Sounds like the work of your average "quality" electrician
As Zarjaz has said; you only need three cores.
Even though the electricians have the wrong colours going into 1, 2, 5 & 6; that doesn't really matter too much (if they're the same on all sockets - You must check this), it just doesn't follow the standard convention.
So; you need to connect (to the faceplate of your master socket);
Green to 2
Orange to 3
White/orange to 4 (although this isn't connected inside the socket, but many electricians will connect it either for neatness, or because they think it does something).
White/green to 5
Leave the blues disconnected.
Or.....Go round all extension sockets (swapping the greens & blues), and use the blue & white/blue in the master, so they're connected properly.
ADSL2+ with BE
DL Sync Blimey....4707kbps now!
UL Sync 1088kbps
DG834GT with DGTeam firmware