No dial tone on home phones after Virgin switch

[#1]

I wonder if anyone has had a similar issue.
I was switched over to Plusnet (from Virgin) yesterday and an engineer re-configured the phone line with a new BT master box.  He tested the line and said everything was fine.  But neither my Panasonic cordless nor an old BT corded phone could get a dial tone.  It was possible to ring into the line using a mobile and Plusnet told me there were no line faults.
Today I bought a cheap new BT corded phone and it works fine.  Using the new cable (between unit and socket) that came with that also makes the old BT corded phone work.  But using that new cable to the base of the Panasonic cordless still doesn't make that work.
is there an issue with compatability of different phones with BT/Plusnet service?  And why would the old phone work with the new cable but not the old - I thought all these cables were standard?
I'd be grateful if anyone has any advice as right now I'm looking at having to buy a new set of (probably BT) cordless phones, which I don't really feel I should have to do. All the phones worked fine with Virgin the day before yesterday
Thanks
Gareth

[#2]

OK, I'll admit I was maybe a little bit quick off the mark here.  It seems you have to use the cable as supplied by the original manufacturer to connect the phone to the socket.  I'd used another longer one to connect the Panasonic cordless base station as I wanted to move it.  But when I replaced the original, all works fine.  May help others!

[#3]

I see you've found out the hard way.
Some manufacturers use a lead which has a RJ11 plug on the end the the "live" two wires are the two middle pins. Other manufacturers use a lead with a straight through configuration and the outer pins carry the signal.

[#4]

As I found out when moving the phone base station out of the hall (ceiling being plastered) and it wouldn't work
The lead looked OK but just didn't work

[#5]

As Dom has mentioned, different manufacturers may use different pins on the connector at the phone end. This is/was the same with dial-up modems as well.