asterisk users - Oct 2006 - Problem with incomming calls

<font size="2">I've got an odd situation where callerid is
only picked up every other call.&nbsp; Is there anything I can do so
callerid works on all calls?<br><br>I'm seeing the channel hangs
up during a call<br><br>&nbsp; == Starting post polarity CID
detection on channel 4<br>&nbsp;&nbsp;&nbsp; -- Starting
simple switch on 'Zap/4-1'<br>Oct 30 10:20:04 NOTICE[31661]:
chan_zap.c:5889 ss_thread: Got event 2 (Ring/Answered)...<br>Oct 30
10:20:06 WARNING[31661]: chan_zap.c:5929 ss_thread: CID timed out waiting for
ring. Exiting simple switch<br>&nbsp;&nbsp;&nbsp; -- Hungup
'Zap/4-1'<br>&nbsp;&nbsp;&nbsp; -- Starting simple
switch on 'Zap/4-1'<br>&nbsp;&nbsp;&nbsp; -- Executing
Answer("Zap/4-1", "") in new
stack<br>&nbsp;&nbsp;&nbsp; -- Executing
NoOp("Zap/4-1", "") in new
stack<br>&nbsp;&nbsp;&nbsp; -- Executing
LookupCIDName("Zap/4-1", "") in new
stack<br><br><br><br>When it works I see
this:<br><br>&nbsp; == Starting post polarity CID detection on
channel 4<br>&nbsp;&nbsp;&nbsp; -- Starting simple switch on
'Zap/4-1'<br>&nbsp;&nbsp;&nbsp; -- Executing
Answer("Zap/4-1", "") in new
stack<br>&nbsp;&nbsp;&nbsp; -- Executing
NoOp("Zap/4-1", "01946622960") in new
stack<br>&nbsp;&nbsp;&nbsp; -- Executing
LookupCIDName("Zap/4-1", "") in new
stack<br><br><br><br><br>zapata.conf<br><br>[channels]<br>switchtype=national<br>usecallerid=yes<br>ukcallerid=yes<br>cidsignalling=v23<br>cidstart=polarity<br>hidecallerid=no<br>sendcalleridafter=2<br>callwaiting=yes<br>;answeronpolarityswitch=no<br>usecallingpres=yes<br>callwaitingcallerid=yes<br>threewaycalling=yes<br>transfer=yes<br>canpark=yes<br>cancallforward=yes<br>callreturn=yes<br>echocancel=yes<br>echocancelwhenbridged=yes<br><br><br><br>TIA<br><br>Phil<br></font>