asterisk users - Nov 2004 - HFS in NT mode getting PRI got event: 6 on Primary D-Channel of span 1

Hello list

We're trying to get a HFC card running in NT mode. Zaphfc loads fine as
module and ztcfg -v is run only once per reboot. Cabling is ok, the
ISDN-TE gets ist power fine. The HFC card does not share any interupts.

After the TE picks up the console (pri debug enabled) shows:
Nov 21 18:42:20 NOTICE[13326]: chan_zap.c:7169 pri_dchannel: PRI got
event: 6 on Primary D-channel of span 1

pri show span 1:
Primary D-channel: 3
Status: Provisioned, Up, Active

Switchtype: EuroISDN
Type: Network (PtMP)
Window Length: 135307692/135307628
Sentrej: 135308140
SolicitFbit: 135308012
Retrans: 135308076
Busy: 135307564
Overlap Dial: -1

zaptel.conf:
span=1,1,3,ccs,ami
bchan=1-2
dchan=3 

zapata.conf
switchtype = euroisdn
language=de
signalling = bri_net_ptmp 
pridialplan=unknown
prilocaldialplan=unknown
pritrustusercid=no
usecallingpres=yes
echocancel=yes
immediate=no
usecallerid=yes
group = 1
context=outgoing
overlapdial=yes
channel => 1-2

Does anyone have any hints?

Many thanks,
Pascal.