asterisk users - Jul 2008 - callerid_get_dtmf: Couldn't detect start-character. CID parsing might be unreliable

Hi list,

My caller ID is not working anymore on my TDM11B (TDM400P) cards and i get 
this error message on the asterisk console:

== Starting post polarity CID detection on channel 4
     -- Starting simple switch on 'Zap/4-1'
[Jul  8 11:58:55] WARNING[9539]: callerid.c:219 callerid_get_dtmf: 
Couldn't detect start-character. CID parsing might be unreliable

A long time ago my CallerID used to work with the same settings. I don't 
really need CallerID but it would be nice to have it working. I am located 
in The Netherlands.

Any suggestions?

This is in my /etc/zaptel.conf :
fxoks=1
fxsks=4 
loadzone=nl 
defaultzone=nl 
This is in my /etc/asterisk/zapata.conf :
echocancel=yes
echocancelwhenbridged=yes
echotraining=400

callerid=202
signalling=fxo_ks
group=1
context=intern-all
channel=>1

signalling=fxs_ks
immediate=yes 
usecallerid=yes
callerid=asreceived
cidsignalling=dtmf
cidstart=polarity
hidecallerid=no
callwaiting=no 
callwaitingcallerid=no
adsi=no 
group=2 
context=inbound-analog
channel=>4