--- asterisk-1.8.0/channels/chan_sip.c.orig	2010-10-23 10:13:37.000000000 -0400
+++ asterisk-1.8.0/channels/chan_sip.c	2010-10-23 10:14:12.000000000 -0400
@@ -11247,6 +11247,9 @@
 		return;
 	}
 
+        if(pvt->owner->redirecting.reason == AST_REDIRECTING_REASON_UNCONDITIONAL)
+                return;
+
 	reason = sip_reason_code_to_str(pvt->owner->redirecting.reason);
 
 	/* We at least have a number to place in the Diversion header, which is enough */