--- asterisk-1.6.2.6/channels/chan_sip.c.orig	2010-03-02 17:19:57.000000000 -0700
+++ asterisk-1.6.2.6/channels/chan_sip.c	2010-03-16 13:08:41.000000000 -0600
@@ -13353,8 +13353,10 @@ static int get_destination(struct sip_pv
 				return -2;
 			}
 		}
-		/* If we have a context defined, overwrite the original context */
-		if (!ast_strlen_zero(domain_context))
+		/* If we don't have a context defined (i.e. we're a guest call),
+		 * overwrite the original context */
+		if (!p->owner && ast_strlen_zero(p->context) &&
+		    !ast_strlen_zero(domain_context))
 			ast_string_field_set(p, context, domain_context);
 	}