--- chan_sip.c.br14.89184.orig	2007-11-13 14:09:36.000000000 +0100
+++ chan_sip.c.br14.89184	2007-11-13 14:35:54.000000000 +0100
@@ -14995,6 +14995,22 @@
 				ast_log(LOG_DEBUG, "Ignoring out of order response %d (expecting %d)\n", seqno, p->ocseq);
 			return -1;
 		} else if (p->ocseq && (p->ocseq != seqno) && (seqno != p->lastnoninvite)) {
+
+			/* If we sent multiple outstanding requests, this incoming response can be a "late" response.
+			 * At least, we must cancel retransmits.
+			 * This is only a workaround until multiple outstanding transactions are fully supported. */
+			if (e && (e = ast_skip_blanks(e)) && sscanf(e, "%d %n", &respid, &len) == 1) {
+				const char *msg = strchr(cseq, ' ');
+				int sipmethod = find_sip_method(msg ? msg + 1 : "");
+
+				if (option_debug > 3)
+					ast_log(LOG_DEBUG, "Cancel retransmits (if any) for CSeq %d Method %s\n", seqno, sip_methods[sipmethod].text);
+				if ((respid >= 100) && (respid <= 199))
+					__sip_semi_ack(p, seqno, 0, sipmethod);
+				else
+					__sip_ack(p, seqno, 0, sipmethod);
+			}
+
 			/* ignore means "don't do anything with it" but still have to 
 			   respond appropriately  */
 			ignore = TRUE;