Comment #14 on issue 1986 by [email protected]: [MSS] New best final proxy responses for reINVITE do not overwrite older responses from previous INVITE
http://code.google.com/p/mobicents/issues/detail?id=1986
Also linked to https://c.na7.visual.force.com/apex/Case_View?id=500A0000006HaPTIA0&sfdc.override=1
