diff --git a/product/ERP5Type/Core/ActionInformation.py b/product/ERP5Type/Core/ActionInformation.py
index 64c3b49e459a30b1c8c3f3482febda3fa6a7cf43..8be6e388d395aae5a299705a8ebedc17cde66253 100644
--- a/product/ERP5Type/Core/ActionInformation.py
+++ b/product/ERP5Type/Core/ActionInformation.py
@@ -32,7 +32,7 @@ import zope.interface
 from AccessControl import ClassSecurityInfo, getSecurityManager
 from Acquisition import aq_base
 from Products.CMFCore.Expression import Expression
-from Products.ERP5Type import interfaces, Constraint, Permissions, PropertySheet
+from Products.ERP5Type import interfaces, Permissions, PropertySheet
 from Products.ERP5Type.Permissions import AccessContentsInformation
 from Products.ERP5Type.XMLObject import XMLObject
 
diff --git a/product/ERP5Type/Core/CacheFactory.py b/product/ERP5Type/Core/CacheFactory.py
index a4383373567d2416a2d1e4304ea06d845cda2d28..da7a4f436f6b9f154fa2746870af689b51ae2ad0 100644
--- a/product/ERP5Type/Core/CacheFactory.py
+++ b/product/ERP5Type/Core/CacheFactory.py
@@ -31,7 +31,6 @@
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 from Products.ERP5Type import PropertySheet
-from Products.ERP5Type.PropertySheet.CacheFactory import CacheFactory
 from Products.ERP5Type.XMLObject import XMLObject
 from Products.ERP5Type.Cache import CachingMethod
 
@@ -57,7 +56,7 @@ class CacheFactory(XMLObject):
   property_sheets = ( PropertySheet.Base
                     , PropertySheet.SimpleItem
                     , PropertySheet.Folder
-                    , CacheFactory
+                    , PropertySheet.CacheFactory
                     )
 
 
diff --git a/product/ERP5Type/Core/Folder.py b/product/ERP5Type/Core/Folder.py
index 58fc2007cede7c7e11dd82ceeadc9778c2f990e8..27a023ceb77f9bde77dfda901b7962e1a4594447 100644
--- a/product/ERP5Type/Core/Folder.py
+++ b/product/ERP5Type/Core/Folder.py
@@ -29,12 +29,11 @@
 
 import transaction
 from AccessControl import ClassSecurityInfo
-from Acquisition import aq_base, aq_self, aq_parent, aq_inner
+from Acquisition import aq_base, aq_parent, aq_inner
 from OFS.History import Historical
-from OFS.Folder import Folder as OFSFolder
 import ExtensionClass
 
-from Products.CMFCore.utils import _getAuthenticatedUser, getToolByName
+from Products.CMFCore.utils import getToolByName
 from Products.CMFCore.exceptions import AccessControl_Unauthorized
 from Products.CMFCore.CMFCatalogAware import CMFCatalogAware
 from Products.CMFCore.PortalFolder import ContentFilter
@@ -43,7 +42,6 @@ from Products.ERP5Type.Base import Base
 from Products.ERP5Type.CopySupport import CopyContainer
 from Products.ERP5Type import PropertySheet
 from Products.ERP5Type.XMLExportImport import Folder_asXML
-from Products.ERP5Type.Cache import CachingMethod
 from Products.ERP5Type.Utils import sortValueList
 from Products.ERP5Type.WebDAVSupport import Folder as WebDAVFolder
 
@@ -72,14 +70,13 @@ except ImportError:
 
 from AccessControl import getSecurityManager
 from Products.ERP5Type import Permissions
-from MethodObject import Method
 from DateTime import DateTime
 from random import randint
 
 
 import os
 
-from zLOG import LOG, PROBLEM, WARNING
+from zLOG import LOG, WARNING
 import warnings
 
 # variable to inform about migration process
diff --git a/product/ERP5Type/Core/MemcachedPlugin.py b/product/ERP5Type/Core/MemcachedPlugin.py
index 56662a815236986771967ee8f08510258f2c8cb7..a1d28048571d019ad864cd1669e5b4f3e8a2be2a 100644
--- a/product/ERP5Type/Core/MemcachedPlugin.py
+++ b/product/ERP5Type/Core/MemcachedPlugin.py
@@ -30,7 +30,6 @@
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type.XMLObject import XMLObject
 from Products.ERP5Type import PropertySheet
-from Products.ERP5Type.PropertySheet.MemcachedPlugin import MemcachedPlugin
 from Products.ERP5Type import Permissions
 from Products.ERP5Type.Tool.MemcachedTool import memcached_dict_pool
 
diff --git a/product/ERP5Type/Core/RoleInformation.py b/product/ERP5Type/Core/RoleInformation.py
index ad078bbf3bcb251114d964c4593f548ff7fcdff6..baeb6230f4f966b9dbac4318f2a209dac82eae6f 100644
--- a/product/ERP5Type/Core/RoleInformation.py
+++ b/product/ERP5Type/Core/RoleInformation.py
@@ -32,9 +32,7 @@ import zope.interface
 from AccessControl import ClassSecurityInfo
 from Acquisition import aq_base
 from Products.ERP5Type.Globals import InitializeClass
-from OFS.SimpleItem import SimpleItem
 
-from Products.CMFCore.utils import getToolByName
 from Products.CMFCore.Expression import Expression
 
 from Products.ERP5Type import interfaces, Permissions, PropertySheet