Is it correct that the BT drop wire only has 2 wires connected in the
junction box?
Yet the output side of the junction box that goes to the actual telephone
sockets has 4 wires. So in effect 2 of these wires weren't doing something
or were they?

When I cut my external cable by accident, I had to connect all 4 wires to
get my broadband working correctly it wouldn't work with 2. Which I can't
fathom out.
However since I had to renew the cabling from the junction box in the loft,
I have only connected 2 wires and the broadband appears to be fine.

Here is a link to the junction box as a picture is worth a 1000 words.
http://i918.photobucket.com/albums/a...r/IMG_4858.jpg

What I'm asking is should I just leave as it is as 2 wires or go back to the
4?

Cheers.