[VoiceOps] Issue with n-way call on Broadworks

Conference URI is configured on AS. Works fine for customers on AMS/SCCP as they originate against the AS. SIP endpoints originate against the NS, NS is returning a "404 Not Found" on the invite to the conference URI. I have a case open with TAC but we have not progressed beyond the "collect 500 log files" stage yet so I am hoping someone else may have run into this. Thanks, Rob