[Serusers] Re: Why Does SER Keep Retransmitting "487 Request Terminated" Messages?

Hi All. I don't know if this problem is related to the re-INVITE problem I posted yesterday http://lists.iptel.org/pipermail/serusers/2005-March/016961.html But it seems that when our Sonus PSTN gateway is invovled in a call where the SIP UA sends a CANCEL before the other party answers, that ser restransmits 487 messages to the SIP UA. When dialing SIP->SIP everything works fine, it's just when the Sonus GW is being accessed that the problem surfaces. It appears that everything has been ACKed, so I'm stumped as to what is happening here. The attached call log shows the complete dialog where my Grandstream UA dialed a PSTN number and cancelled the call when the other side was ringing. Can anyone give me a pointer as to why this might be? Regards, Paul