--- channels/chan_sip.c.2010-12-16	2010-12-16 11:30:27.000000000 -0700
+++ channels/chan_sip.c	2010-12-16 15:07:29.000000000 -0700
@@ -27627,10 +27627,12 @@
 	if (!ast_bridged_channel(chan) && !sip_cfg.directrtpsetup) 	/* We are in early state */
 		return 0;
 
+	ast_channel_lock(chan);
 	sip_pvt_lock(p);
 	if (p->alreadygone) {
 		/* If we're destroyed, don't bother */
 		sip_pvt_unlock(p);
+		ast_channel_unlock(chan);
 		return 0;
 	}
 
@@ -27639,6 +27641,7 @@
 	*/
 	if (nat_active && !ast_test_flag(&p->flags[0], SIP_DIRECT_MEDIA_NAT)) {
 		sip_pvt_unlock(p);
+		ast_channel_unlock(chan);
 		return 0;
 	}
 
@@ -27681,6 +27684,7 @@
 	/* Reset lastrtprx timer */
 	p->lastrtprx = p->lastrtptx = time(NULL);
 	sip_pvt_unlock(p);
+	ast_channel_unlock(chan);
 	return 0;
 }