Phone-line problems

[Agent]

Ok, this is a weird one, and its driving me around the bend at the moment.

Its a bit hard to explain, but ill try.
We have a dial-tone, ADSL is running fine, and can make a receive calls.
However, if we have an INCOMING call to the phone, have the conversation, then try and hang up, the line will stay active until the other person hangs up.
When this happens we can hear our selfs talking back, in what i can only describe as a "digitized" version of our voice - almost like an alien.
This is made more confusing by the fact that if we make an OUTGOING call, the line will cease as soon as we press the hang up button, and are free to make calls as fast as we can pick the phone up again.

Its driving me mad. The phone-line has been playing up for a bit now, Ive managed to nail most of the problems on dodgy internal wiring, which has now been replaced with CAT5e.

Any offers ? no matter how silly they may sound, throw them my way !!

[Jiff Lemon]

How many extensions are in the house? You've not gone over your REN allowance?
ADSL works on 2 of the twisted pair, the phone works over the other 4. All the sockets wired correctly? Only takes one of them to bugger the job the up.