--- a/dataimport.py	Tue Jun 07 12:54:45 2011 +0200
+++ b/dataimport.py	Tue Jun 07 16:07:06 2011 +0200
@@ -642,7 +642,9 @@
         for k, v in kwargs.iteritems():
             kwargs[k] = getattr(v, 'eid', v)
         entity, rels = self.metagen.base_etype_dicts(etype)
+        # make a copy to keep cached entity pristine
         entity = copy(entity)
+        entity.cw_edited = copy(entity.cw_edited)
         entity.cw_clear_relation_cache()
         self.metagen.init_entity(entity)
         entity.cw_edited.update(kwargs, skipsec=False)

--- a/server/edition.py	Tue Jun 07 12:54:45 2011 +0200
+++ b/server/edition.py	Tue Jun 07 16:07:06 2011 +0200
@@ -68,6 +68,11 @@
         super(EditedEntity, self).__delitem__(attr)
         self.entity.cw_attr_cache.pop(attr, None)
 
+    def __copy__(self):
+        # default copy protocol fails in EditedEntity.__setitem__ because
+        # copied entity has no skip_security attribute at this point
+        return EditedEntity(self.entity, **self)
+
     def pop(self, attr, *args):
         # don't update skip_security by design (think to storage api)
         assert not self.saved, 'too late to modify edited attributes'