Index: chan_sip.c
===================================================================
--- chan_sip.c	(revision 184953)
+++ chan_sip.c	(working copy)
@@ -3711,6 +3711,7 @@
 			continue;
 		if (cur->is_resp || cur->method == sipmethod) {
 			msg = "Found";
+			p->invitestate = INV_TERMINATED;
 			if (!resp && (seqno == p->pendinginvite)) {
 				ast_debug(1, "Acked pending invite %d\n", p->pendinginvite);
 				p->pendinginvite = 0;
@@ -20545,15 +20546,14 @@
 	case SIP_ACK:
 		/* Make sure we don't ignore this */
 		if (seqno == p->pendinginvite) {
-			p->invitestate = INV_TERMINATED;
 			p->pendinginvite = 0;
-			__sip_ack(p, seqno, 1 /* response */, 0);
 			if (find_sdp(req)) {
 				if (process_sdp(p, req, SDP_T38_NONE))
-					return -1;
+				return -1;
 			} 
-			check_pendings(p);
 		}
+		__sip_ack(p, seqno, 1 /* response */, 0);
+		check_pendings(p);
 		/* Got an ACK that we did not match. Ignore silently */
 		if (!p->lastinvite && ast_strlen_zero(p->randdata)) {
 			pvt_set_needdestroy(p, "unmatched ACK");