asterisk users - Nov 2005 - Cadence, distinctive ringing and zapata.conf

I've been having trouble defining distinctive ringing as described here:

http://www.voip-info.org/wiki/index.php?page=Asterisk+Zap+channels

It suggests adding cadence= lines to your zapata.conf file. The format
for the cadence command is ontime,offtime,ontime,offtime .... etc in
mS

I did that, but when I run:

/sbin/ztcfg -vvvv

I get:

Invalid keyword cadence

Any idea what's wrong or how I set up distinctive ringing?

Also you can see from my zaptel.conf below that defaultzone=us, yet
when my dialplan executes Dial(ZAP/1,20,t), i.e. I don't specify a
distinctive ringtone, I get a "chirp" ringtone, not the standard North
American tone.  Any ideas on why?

Thanks,
Hugh

loadzone=us
defaultzone=us
#
# CADENCE NOT WORKING!!
#===== Cadences ====#		Ring	Pause
#Standard	3000	4000
#
#Standard ring, standard pause
#cadence=3000,4000
#
#Chirp, pause, short ring, short pause
#cadence=500,750,2000,3000
#
#Chirp
#cadence=500,750
#
#Progressively longer
#cadence=500,750,1000,1500,2000,3000,3000,4500
#
fxsks=3-4
fxoks=1-2