--- a/frontends/src/wix/contact_list.py	Sun Jun 08 17:39:21 2014 +0200
+++ b/frontends/src/wix/contact_list.py	Thu May 29 14:34:01 2014 +0200
@@ -79,11 +79,16 @@
     def replace(self, contact, groups=None, attributes=None):
         """Add a contact to the list if doesn't exist, else update it.
 
+        This method can be called with groups=None for the purpose of updating
+        the contact's attributes (e.g. nickname). In that case, the groups
+        attribute must not be set to the default group but ignored. If not,
+        you may move your contact from its actual group(s) to the default one.
+
+        None value for 'groups' has a different meaning than [None] which is for the default group.
+
         @param jid (JID)
         @param groups (list): list of groups or None to ignore the groups membership.
         @param attributes (dict)
-
-        XXX: None value for 'groups' has a different meaning than [None] which is for the default group.
         """
         log.debug(_("update %s") % contact)
         if not self.__find_idx(contact):