To Barry: I have never shown any mos code for copying. So you must have mixed people up.
I have never used dialog module, since I don't believe it is the job of sip proxy to deal with dialogs.
I just did a simple test where placed the xinfo call after rtpengine_delete() call and got to syslog:
May 14 17:59:01 lohi /usr/bin/sip-proxy[29816]: INFO: ===== rtpengine_delete() May 14 17:59:01 lohi /usr/bin/sip-proxy[29816]: INFO: mos_avg=4.3 packetloss_avg=0 jitter_avg=4 roudtrip_avg=6814
-- Juha