diff -Naur asterisk-1.4.27.1.orig/channels/chan_sip.c asterisk-1.4.27.1/channels/chan_sip.c
--- asterisk-1.4.27.1.orig/channels/chan_sip.c	2009-12-03 01:29:41.000000000 +0000
+++ asterisk-1.4.27.1/channels/chan_sip.c	2009-12-03 10:17:00.000000000 +0000
@@ -2157,11 +2157,7 @@
 		if (option_debug > 2)
 			ast_log(LOG_DEBUG, "Re-scheduled destruction of SIP call %s\n", p->callid ? p->callid : "<unknown>");
 		append_history(p, "ReliableXmit", "timeout");
-		if (sscanf(p->lastmsg, "Tx: %30s", method_str) == 1 || sscanf(p->lastmsg, "Rx: %30s", method_str) == 1) {
-			if (method_match(SIP_CANCEL, method_str) || method_match(SIP_BYE, method_str)) {
-				ast_set_flag(&p->flags[0], SIP_NEEDDESTROY);
-			}
-		}
+		ast_set_flag(&p->flags[0], SIP_NEEDDESTROY);
 		return 10000;
 	}