Personall I would take nothing for granted.
A few pointers.
First its unlikely the bell wire is causing crackle on your line.
By connecting your telephone to the test socket and no noise proves the noise is internal and therefore your problem
If you believe the crackle is having an adverse effect on your broadband connection then connect your router to the master test socket.
Its obvious the colour code has been ignored be careful what you disconnect and be prepared to reconnect. In fact the connected colours could be an indication of a wiring problem hence the wrong colours used.
report the noise to BT.
Edited by wireman100 (Sun 21-Oct-07 20:07:28)