asterisk users - Oct 2003 - Three way calling problems: 2 ea. X100P 1 ea TDM10p

I'm having a problem getting 3 way calling to work correctly using two
outside lines and one extension. The two outside lines are connected
to the X100P's and a standard model 2500 phone is connected to the
TDM10.

When I dial the first outside destination 9xxxxxxx, the call completes
correctly. When I flash the hook switch and dial the second location
9yyyyyyy. The call doesn't complete, and most of the time (but not always)
the dial tone is not broken by the digit following the '9'.

My configuration files are:

#
# zaptel.conf
#
                                                                                
fxsks=1-2
fxoks=3
loadzone = us
defaultzone=us
#
# End of file
#
;
; zapata.conf
;
                                                                                
[channels]
;
; 2 ea. X100P plugged into PSTN
;
context=from-pstn
signalling=fxs_ks
echocancel=yes
echocancelwhenbridged=yes
relaxdtmf=yes
rxgain=1
txgain=1
immediate=no
busydetect=no
callprogress=no
musiconhold=default
usecallerid=no
;callerid=asreceived
channel=1-2
;
; TDM100B Port #1 plugged into analog Phone
; This phone is allowed to dial extensions and local and long distance numbers
;
context=from-analog-phones
signalling=fxo_ks
callwaiting=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
echocancel=yes
echocancelwhenbridged=yes
relaxdtmf=yes
rxgain=1
txgain=1
immediate=no
musiconhold=default
usecallerid=yes
callerid="TDM100 Zap Phone" <103>
channel=3
;
; End of file
;

;
; extensions.conf
;
[general]
                                                                                
static=yes       ; These two lines prevent the command-line interface
writeprotect=yes ; from overwriting the config file. Leave them here.
                                                                                
[globals]
                                                                                
[aliens]
                                                                                
;
; Take unknown callers that may have found
; our system, and send them to a re-order tone.
; The string "_." matches any dialed sequence, so all
; calls will result in the Congestion tone application
; being called. They'll get bored and hang up eventually.
;
                                                                                
exten => _.,1,Congestion
                                                                                
;
; Local calls
;
                                                                                
[pstn-local]
;
                                                                                
exten => _9NXXXXXX,1,Dial,Zap/1/9www${EXTEN:1}
exten => _9NXXXXXX,2,Dial,Zap/2/9www${EXTEN:1}
exten => _9NXXXXXX,3,Congestion
                                                                                
                                                                                
;
; This is the context which all house phones see
;
                                                                                
[house-phones]
                                                                                
include => pstn-local
                                                                                
[from-analog-phones]
ignorepat => 9
include => house-phones
                                                                                
;
; End of File
;

Note: I've simplified my configuration to try and get it to a minimal state
which causes the problem for clarity. The above configuration files will 
exhibit the problem on  the latest CVS version checked out at
8:00pst October 30 2003. 

                                                                                
Thanks

Steve Rodgers
San Diego, CA