--- asterisk-1.8.9.1/channels/chan_sip.c	2012-02-06 22:40:37.000000000 +0100
+++ /root/asterisk-1.8.9.1/channels/chan_sip.c	2012-02-08 15:30:04.552673312 +0100
@@ -20952,6 +20952,17 @@ static void handle_response(struct sip_p
 		case 481: /* Call leg does not exist */
 			if (sipmethod == SIP_INVITE) {
 				handle_response_invite(p, resp, rest, req, seqno);
+			}
+			else if (sipmethod == SIP_UPDATE) {
+				switch (resp) {
+					case 481: /* Call leg does not exist */
+	                			ast_log(LOG_WARNING, "Re-invite with UPDATE to non-existing call leg on other UA. SIP dialog '%s'. Giving up.\n", p->callid);
+        	        			//xmitres = transmit_request(p, SIP_ACK, seqno, XMIT_UNRELIABLE, FALSE);
+                				if (p->owner)
+                        				ast_queue_control(p->owner, AST_CONTROL_CONGESTION);
+                				sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
+                				break;
+				}
 			} else if (sipmethod == SIP_SUBSCRIBE) {
 				handle_response_subscribe(p, resp, rest, req, seqno);
 			} else if (sipmethod == SIP_BYE) {