Get CDR ANSWER when call is NOT answered

Hi All,

I have this problem that I guess there may be some post on it,but I could not find it.

We have the following configuration that can work for a call shop:
IP T1 Analog
Sip phone <–> Asterisk <—> Rhino Channel Bank <—> PSTN

We call from the Sip phone to any phone through PSTN using any of the T1 zap channels.
The problem is that as soon as the SIP phone dials, the Zap answers and set the status of the channel as ANSWERED!.
Now this cause problems because when we dial from the SIP phone and disconnect after few seconds (during ring back for example) then the call appears in CDR as ANSWERED even that it was NOT answered!!

The dial plan is very simple:
exten => _X.,1,Set(DST=${EXTEN})
exten => _X.,n,Dial(Zap/9/${DST}|30)
exten => _X.,n,Hangup

zpata.conf is std with:
callprogress=no ; tried also yes
busydetect=yes
busycount=4
busypattern=500,500
hanguponpolarityswitch=no
answeronpolarityswitch=no

Any advice for possible solution will be appreciated.

Thanks