Index: res/res_sip_session.c
===================================================================
--- res/res_sip_session.c	(revision 393906)
+++ res/res_sip_session.c	(working copy)
@@ -1678,7 +1678,7 @@
 				if (tsx->status_code == PJSIP_SC_REQUEST_PENDING) {
 					reschedule_reinvite(session, tsx->mod_data[session_module.id], tsx->last_tx);
 					return;
-				} else {
+				} else if (inv->state == PJSIP_INV_STATE_CONFIRMED) {
 					/* Other failures result in destroying the session. */
 					pjsip_tx_data *tdata;
 					pjsip_inv_end_session(inv, 500, NULL, &tdata);