diff --git a/libs/sofia-sip/.update b/libs/sofia-sip/.update
index f3382220ab..6b6f901a57 100644
--- a/libs/sofia-sip/.update
+++ b/libs/sofia-sip/.update
@@ -1 +1 @@
-Wed Feb 11 10:16:40 CST 2009
+Wed Feb 11 10:18:18 CST 2009
diff --git a/libs/sofia-sip/libsofia-sip-ua/iptsec/auth_client.c b/libs/sofia-sip/libsofia-sip-ua/iptsec/auth_client.c
index 20d1287204..1feb81d66d 100644
--- a/libs/sofia-sip/libsofia-sip-ua/iptsec/auth_client.c
+++ b/libs/sofia-sip/libsofia-sip-ua/iptsec/auth_client.c
@@ -128,11 +128,17 @@ int auc_challenge(auth_client_t **auc_list,
     if (!matched) {
       /* There was no matching authenticator, create a new one */
       *cca = ca_create(home, scheme, realm);
-      if (ca_challenge((*cca), ch, crcl, scheme, realm) < 0) {
+
+      if (*cca == NULL) {
+	return -1;
+      }
+      else if (ca_challenge((*cca), ch, crcl, scheme, realm) < 0) {
 	ca_destroy(home, *cca), *cca = NULL;
 	return -1;
       }
-      retval = 1;		/* Updated authenticator */
+      /* XXX - case w/ unknown authentication scheme */
+      else
+	retval = 1;		/* Updated authenticator */
     }
   }
 
diff --git a/libs/sofia-sip/libsofia-sip-ua/iptsec/sofia-sip/auth_client_plugin.h b/libs/sofia-sip/libsofia-sip-ua/iptsec/sofia-sip/auth_client_plugin.h
index 36104ec8bd..cc1d2d83cf 100644
--- a/libs/sofia-sip/libsofia-sip-ua/iptsec/sofia-sip/auth_client_plugin.h
+++ b/libs/sofia-sip/libsofia-sip-ua/iptsec/sofia-sip/auth_client_plugin.h
@@ -98,7 +98,8 @@ struct auth_client_plugin
 
 /** Check if authentication client has been extended. @NEW_1_12_6. */
 #define AUTH_CLIENT_IS_EXTENDED(ca)					\
-  ((ca)->ca_auc->auc_plugin_size >					\
+  ((ca)->ca_auc &&							\
+   (ca)->ca_auc->auc_plugin_size >					\
    (int)offsetof(auth_client_plugin_t, auc_clear)			\
    && (ca)->ca_auc->auc_clear != NULL)