Repetitive chan_zap.c warning (possible misconfiguration)

The setup:
Asterisk 1.2.7.1 (Asterisk@HOME 2.8), bristuff 0.3.0-PRE-1o and a Junghanns quadBRI ISDN card.

I keep getting several MBytes of logs with the following messages:

==> /var/log/asterisk/full <== May 11 15:42:07 VERBOSE[3308] logger.c: == Primary D-Channel on span 4 down May 11 15:42:07 WARNING[3308] chan_zap.c: No D-channels available! Using Primary channel 12 as D-channel anyway! May 11 15:42:07 VERBOSE[3307] logger.c: == Primary D-Channel on span 3 down May 11 15:42:07 WARNING[3307] chan_zap.c: No D-channels available! Using Primary channel 9 as D-channel anyway!

Also, kernel reports:

==> /var/log/messages <== May 11 15:42:15 asterisk1 kernel: qozap: CRC error for HDLC frame on card 1 (cardID 0) S/T port 3 May 11 15:42:48 asterisk1 kernel: qozap: CRC error for HDLC frame on card 1 (cardID 0) S/T port 3 May 11 15:44:21 asterisk1 kernel: qozap: CRC error for HDLC frame on card 1 (cardID 0) S/T port 3 May 11 15:45:47 asterisk1 kernel: qozap: CRC error for HDLC frame on card 1 (cardID 0) S/T port 3 May 11 15:47:03 asterisk1 kernel: qozap: CRC error for HDLC frame on card 1 (cardID 0) S/T port 3 May 11 15:48:20 asterisk1 last message repeated 4 times

Related configuration files:

/etc/zaptel.conf

loadzone=nl
defaultzone=nl
# qozap span definitions
# most of the values should be bogus because we are not really zaptel
span=1,1,3,ccs,ami
span=2,0,3,ccs,ami
span=3,0,3,ccs,ami
span=4,0,3,ccs,ami

bchan=1,2
dchan=3
bchan=4,5
dchan=6
bchan=7,8
dchan=9
bchan=10,11
dchan=12 

/etc/asterisk/zapata.conf

[channels]
musiconhold=default
switchtype = euroisdn

pridialplan = local
prilocaldialplan = local

echotraining=no
echocancel = yes
immediate=yes

signalling = bri_cpe
context=isdn_in

group = 1
;; S/T port 1
channel => 1-2

group = 2
;; S/T port 2
channel => 4-5

signalling = bri_cpe
context=isdn_pbx

group = 3
;; S/T port 3
channel => 7-8

group = 4
;; S/T port 4
channel => 10-11

Any ideas?

Thanks for your time,

Michael

Who is your ISDN provider?