diff --git a/product/ERP5/Document/ImmobilisableItem.py b/product/ERP5/Document/ImmobilisableItem.py
index 1cc9edbe313d6a9139b07cbda6865907abf00805..97290bf48fe76d1061064704032b1605d8d315f5 100755
--- a/product/ERP5/Document/ImmobilisableItem.py
+++ b/product/ERP5/Document/ImmobilisableItem.py
@@ -881,20 +881,20 @@ class ImmobilisableItem(XMLObject, Amount):
     #         'annuity_start_date':          annuity_start_date,
             })
         try:
-          ratio_script = self.unrestrictedTraverse('portal_skins/%s' % amortisation_method).ratioCalculation
+          ratio_script = self.unrestrictedTraverse(amortisation_method).ratioCalculation
         except KeyError:
           LOG('ERP5 Warning :', 0,
               'Unable to find the ratio calculation script %s for item %s at date %s' % (
-                 'portal_skins/%s/ratioCalculation' % amortisation_method, self.getRelativeUrl(), repr(at_date)))
+                 '%s/ratioCalculation' % amortisation_method, self.getRelativeUrl(), repr(at_date)))
           raise ImmobilisationCalculationError, \
               'Unable to find the ratio calculation script %s for item %s at date %s' % (
-                 'portal_skins/%s/ratioCalculation' % amortisation_method, self.getRelativeUrl(), repr(at_date))
+                 '%s/ratioCalculation' % amortisation_method, self.getRelativeUrl(), repr(at_date))
               
         current_ratio = ratio_script(**ratio_params)
         if current_ratio is None:
           LOG("ERP5 Warning :",0,
               "Unable to calculate the ratio during the amortisation calculation on item %s at date %s : script %s returned None" % (
-                  self.getRelativeUrl(), repr(at_date), 'portal_skins/%s/ratioCalculation' % amortisation_method))
+                  self.getRelativeUrl(), repr(at_date), '%s/ratioCalculation' % amortisation_method))
           LOG('params were ', 0, ratio_params) 
           raise ImmobilisationCalculationError, \
               "Unable to calculate the ratio during the amortisation calculation on item %s at date %s" % (
diff --git a/product/ERP5/Document/ImmobilisationMovement.py b/product/ERP5/Document/ImmobilisationMovement.py
index 0b909f0fa2897b22017b52fc0cf1d0795cd180e7..8b8116a4552ab2166265def28c5db10fd4e924ce 100755
--- a/product/ERP5/Document/ImmobilisationMovement.py
+++ b/product/ERP5/Document/ImmobilisationMovement.py
@@ -43,7 +43,7 @@ from zLOG import LOG
 
 UNIMMOBILISING_METHOD = "unimmobilise"
 NO_CHANGE_METHOD = "no_change"
-AMORTISATION_METHOD_PREFIX = "erp5_accounting_"
+AMORTISATION_METHOD_PREFIX = "portal_skins/erp5_accounting_"
 IMMOBILISATION_NEEDED_PROPERTY_LIST = [
               ("date",   "stop_date",           "Date"),
               ("method", "amortisation_method", "Amortisation Method"),
@@ -270,7 +270,7 @@ class ImmobilisationMovement(Movement, XMLObject):
       parameter_dict[parameter] = None
     amortisation_method = self.getActualAmortisationMethodForItem(item, **kw)
     if amortisation_method not in (None, NO_CHANGE_METHOD, UNIMMOBILISING_METHOD, ""):
-      parameter_object = self.restrictedTraverse(AMORTISATION_METHOD_PREFIX + amortisation_method)
+      parameter_object = self.unrestrictedTraverse(AMORTISATION_METHOD_PREFIX + amortisation_method)
       if parameter_object is not None:
         for parameter in parameter_list:
           parameter_dict[parameter] = getattr(parameter_object, parameter, None)