asterisk users - Jun 2006 - Random Zap Channel Drops to SIP

Asterisk Version: 1.2.9.1
Zaptel Version: 1.2.6
LibPri Version: 1.2.3

Hey List,

we are running an asterisk server in connection with an octopus 
telephone system. I have expired some random drops of zap channels
bridged to SIP Telefones ( snom 190 ). Asterisk Messages shows something 
like that:

Jun  9 09:32:33 WARNING[3207] res_features.c: Bridge failed on channels 
SIP/fon01-6945 and Zap/32-1

This is my zapata.conf :

switchtype=qsig
pridialplan=unknown
prilocaldialplan=unknown
internationalprefix=00
nationalprefix=0
usecallingpres=yes
callwaitingcallerid=yes
echotraining=500
echocancel=yes
echocancelwhenbridged=no
transfer=yes
cancallforward=yes
callreturn=no
busydetect=no
threewaycalling=yes
callprogress=no
overlapdial=yes
callwaiting=no
usecallingpres=yes
immediate=no
usecallerid=yes
hidecallerid=no
restrictcid=no
callerid=asreceived
language=de
rxgain=2.5
txgain=-0.5
group=2
signalling=pri_net
channel => 32-46,48-62

I Hope someone could help in this case. Thank you in advice

Greetings,
 Michael

I'm am experiencing the same issue after upgrading from 1.2.0, still trying
to track down any info on it.
>w are running an asterisk server in connection with an octopus telephone
system. I have expired 
>some random drops of zap channels bridged to SIP Telefones ( snom 190 ). A
>sterisk Messages shows something like that:
>Jun  9 09:32:33 WARNING[3207] res_features.c: Bridge failed on channels
>SIP/fon01-6945 and Zap/32-1