diff --git a/VERSION b/VERSION
index 4cc2f05c..cecfebc4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-Version 2.6.4-stable+timestamp.2013.10.04.14.38.32
+Version 2.6.4-stable+timestamp.2013.10.04.14.40.29
diff --git a/gluon/contrib/login_methods/ldap_auth.py b/gluon/contrib/login_methods/ldap_auth.py
index 0c832880..49ebae99 100644
--- a/gluon/contrib/login_methods/ldap_auth.py
+++ b/gluon/contrib/login_methods/ldap_auth.py
@@ -641,6 +641,9 @@ def ldap_auth(server='ldap', port=None,
                 # bind as anonymous
                 con.simple_bind_s('', '')
 
+       # if username is None, return empty list
+       if username is None:
+               return list()
         # search for groups where user is in
         filter = '(&(%s=%s)(%s))' % (ldap.filter.escape_filter_chars(
                                                             group_member_attrib