diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 29b92a51ce..f6fb2af7ca 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -23208,9 +23208,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 				}
 			}
 			transmit_response_reliable(p, "491 Request Pending", req);
-			p->pendinginvite = seqno;
 			check_via(p, req);
-			copy_request(&p->initreq, req);
 			ast_debug(1, "Got INVITE on call where we already have pending INVITE, deferring that - %s\n", p->callid);
 			/* Don't destroy dialog here */
 			res = INV_REQ_FAILED;
@@ -23230,7 +23228,6 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 		if (p->owner) {
 			ast_debug(3, "INVITE w Replaces on existing call? Refusing action. [%s]\n", p->callid);
 			transmit_response_reliable(p, "400 Bad request", req);	/* The best way to not not accept the transfer */
-			p->pendinginvite = seqno;
 			check_via(p, req);
 			copy_request(&p->initreq, req);
 			/* Do not destroy existing call */
@@ -23250,7 +23247,6 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 			sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
 			p->invitestate = INV_COMPLETED;
 			res = INV_REQ_ERROR;
-			p->pendinginvite = seqno;
 			check_via(p, req);
 			copy_request(&p->initreq, req);
 			goto request_invite_cleanup;
@@ -23355,7 +23351,6 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 			refer_locked = 0;
 			p->invitestate = INV_COMPLETED;
 			res = INV_REQ_ERROR;
-			p->pendinginvite = seqno;
 			check_via(p, req);
 			copy_request(&p->initreq, req);
 			goto request_invite_cleanup;
@@ -26208,13 +26203,13 @@ static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct as
 			if (!req->ignore && req->method == SIP_INVITE) {
 				transmit_response_reliable(p, "481 Call/Transaction Does Not Exist", req);
 				/* Will cease to exist after ACK */
+				return res;
 			} else if (req->method != SIP_ACK) {
 				transmit_response(p, "481 Call/Transaction Does Not Exist", req);
 				sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
-			} else {
-				ast_debug(1, "Got ACK for unknown dialog... strange.\n");
+				return res;
 			}
-			return res;
+			/* Otherwise, this is an ACK. It will always have a to-tag */
 		}
 	}