[reSIProcate] help exception

["maodonghu" <hhmmdd@xxxxxxx>]

resip all,

I registered 2 account(dum) in my program to proxy, and use one account to call 
another one, After Make call, 

onNewSession(ClientInviteSessionHandle h, InviteSession::OfferAnswerType oat, 
const SipMessage& msg)
{
        TSipCall* call = (TSipCall*)(h->getAppDialogSet().get());
        call->is = h.get();
        ...
        ...
}

will be called, it runing normal, But occasionally, this function will cause 
exception: access violation at h->getAppDialogSet().get() , I debug, when 
exception, the msg is

SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 
127.0.0.1:3700;branch=z9hG4bK-d87543-0008e60020345407-1--d87543-;rport=3700;received=192.168.101.58
Record-Route: <sip:192.168.101.58:5060;lr>
Contact: <sip:255@xxxxxxxxxxxxxx:5060>
To: <sip:255@xxxxxxxxxxxxxx>;tag=ef685d00
From: "250"<sip:250@xxxxxxxxxxxxxx>;tag=a02e6757
Call-ID: 7c7de54e6758f97f@ZXdpbmdzLW42OXA3MjE0
CSeq: 1 INVITE
User-Agent: eWings-NetVoice/3.0
Content-Length: 0


              I don't know how to resolve it

PS, My make like this:

call = new TSipCall(account->mDum, this);
...
...
SdpContents sdp(&hfv, type);
SharedPtr<SipMessage> inv = account->mDum.makeInviteSession(NameAddr(target), 
&sdp, call);
account->mDum.send(inv);



　　　　　　　　maodonghu
　　　　　　　　hhmmdd@xxxxxxx
　　　　　　　　　　2006-08-11