TDM400P - 1FXO connected to french POTS -> scratches on c

Hye all.
I’ve installed a brand new Wildcard TDM400P with 1 FXO module, plugged on a France Telecom POTS.
Every calls through this channel are horribles, scratched.

I’ve tested fxotune -i 4 and then fxotune -s -> not better.

My configuration is this:

Debian 3.1 Sarge (2.6.8 kernel)
Dell Poweredge SC420 (anyone suppose it can come from here?)
Asterisk 1.0.9
1 Digium TDM400P with 1 FXO Module
1 AVM Fritz card

and the zapata.conf

[channels]
usecallerid => no
callwaiting => yes
callwaitingcallerid => yes
threewaycalling => no
transfer => no
cancallforward => yes
callreturn => yes
language => fr

; module FXO
signalling => fxs_ks
i;cidsignalling => v23
cidstart => ring
busydetect =>yes
busycount => 5
echocancel => yes
echotraining => yes
echocancelwhenbridged => yes
rxgain => 0.0
txgain => 0.0
context => fromanalogique
group => 1
callgroup => 1
pickupgroup => 1
channel => 1

Thanks for your help.
This config is for a customer… :wink:

My question is obsolete in the sense that using another SIP client (I’used to use Eyebeam and now I use a SNOM 360) the calls are perfectly clear, fluent…
Thank u SNOM!