I have just bought a new Beocom 6000. It is connected into the same socket as Beotalk 1200 answerphone and BT Infinity Fibre Optic Broadband with the appropriate filters. very often when trying to make a call the phone sends out the pulses but I continue to hear dial tone. BT have done in depth checks on their system and even replaced the Home Hub. Can anyone suggest a solution please?