diff --git a/test/auto/test_auto.py b/test/auto/test_auto.py
index 70ad642..040e349 100644
--- a/test/auto/test_auto.py
+++ b/test/auto/test_auto.py
@@ -10,7 +10,6 @@ from tiramisu import Config, MetaConfig, \
                      StrOption, SymLinkOption, OptionDescription, MasterSlaves, DynOptionDescription, \
                      getapi, submulti, undefined, owners, Params, ParamOption
 from tiramisu.error import PropertiesOptionError, APIError, ConfigError, SlaveError
-from tiramisu.api import display_count
 from collections import OrderedDict
 ICON = u'\u2937'
 
@@ -1772,4 +1771,3 @@ def test_options(paths):
                                                       weakrefs, **get_kwargs(lpath))
                                     del cfg
                                     check_deref(weakrefs)
-    display_count()
diff --git a/tiramisu/api.py b/tiramisu/api.py
index c0fa341..92d8f39 100644
--- a/tiramisu/api.py
+++ b/tiramisu/api.py
@@ -115,18 +115,20 @@ class CommonTiramisu(TiramisuHelp):
                                        self.option_bag.path,
                                        self.option_bag.index,
                                        self.option_bag.config_bag)
-        index = self.option_bag.index
-        if index is not None:
-            if option.impl_is_optiondescription() or not option.impl_is_master_slaves('slave'):
-                raise APIError('index must be set only with a slave option')
-            self._length = self.subconfig.cfgimpl_get_length_slave(self.option_bag)
-            if index >= self._length:
-                raise SlaveError(_('index "{}" is higher than the master length "{}" '
-                                   'for option "{}"').format(index,
-                                                             self._length,
-                                                             option.impl_get_display_name()))
-        if not self.allow_optiondescription and option.impl_is_optiondescription():
-            raise APIError(_('option must not be an optiondescription'))
+            if self.option_bag.config_bag.setting_properties:
+                self.option_bag.config_bag.context.cfgimpl_get_settings().validate_properties(self.option_bag)
+            index = self.option_bag.index
+            if index is not None:
+                if option.impl_is_optiondescription() or not option.impl_is_master_slaves('slave'):
+                    raise APIError('index must be set only with a slave option')
+                self._length = self.subconfig.cfgimpl_get_length_slave(self.option_bag)
+                if index >= self._length:
+                    raise SlaveError(_('index "{}" is higher than the master length "{}" '
+                                       'for option "{}"').format(index,
+                                                                 self._length,
+                                                                 option.impl_get_display_name()))
+            if not self.allow_optiondescription and option.impl_is_optiondescription():
+                raise APIError(_('option must not be an optiondescription'))
         return option
 
 
@@ -504,7 +506,7 @@ class TiramisuOption(CommonTiramisu):
             return self.registers[subfunc](self._name,
                                            self.subconfig,
                                            self.option_bag)
-        elif self._get_option().impl_is_optiondescription():
+        elif self._get_option().impl_is_optiondescription() and not subfunc.startswith('_'):
             return getattr(self, '_' + subfunc)
         raise APIError(_('please specify a valid sub function ({})').format(subfunc))
 
diff --git a/tiramisu/config.py b/tiramisu/config.py
index a213a1c..944f1b9 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -249,24 +249,17 @@ class SubConfig(object):
                 option_bag,
                 _commit=True):
 
-        #self, name = self.cfgimpl_get_home_by_path(option_bag.path,
-        #                                           option_bag.config_bag)
-        #if config_bag.option is None:
-        #    config_bag.option = self.cfgimpl_get_description().impl_getchild(name,
-        #                                                                     config_bag,
-        #                                                                     self)
         if option_bag.option.impl_is_symlinkoption():
             raise ConfigError(_("can't assign to a SymLinkOption"))
-        else:
-            context = self.cfgimpl_get_context()
-            if option_bag.config_bag.setting_properties:
-                context.cfgimpl_get_settings().validate_properties(option_bag)
-            self.cfgimpl_get_description().impl_validate_value(option_bag.option,
-                                                               value,
-                                                               self)
-            return context.cfgimpl_get_values().setvalue(value,
-                                                         option_bag,
-                                                         _commit)
+        context = option_bag.config_bag.context
+        if option_bag.config_bag.setting_properties:
+            context.cfgimpl_get_settings().validate_properties(option_bag)
+        self.cfgimpl_get_description().impl_validate_value(option_bag.option,
+                                                           value,
+                                                           self)
+        return context.cfgimpl_get_values().setvalue(value,
+                                                     option_bag,
+                                                     _commit)
 
     def delattr(self,
                 option_bag):
@@ -812,25 +805,27 @@ class GroupConfig(_CommonConfig):
         """
         ret = []
         for child in self._impl_children:
+            cconfig_bag = config_bag.copy()
+            cconfig_bag.context = child
             try:
                 if isinstance(child, GroupConfig):
                     ret.extend(child.set_value(path,
                                                index,
                                                value,
-                                               config_bag,
+                                               cconfig_bag,
                                                only_config=only_config,
                                                _commit=False))
                 else:
                     subconfig, name = child.cfgimpl_get_home_by_path(path,
-                                                                     config_bag)
+                                                                     cconfig_bag)
                     option = subconfig.cfgimpl_get_description().impl_getchild(name,
-                                                                               config_bag,
+                                                                               cconfig_bag,
                                                                                child)
                     option_bag = OptionBag()
                     option_bag.set_option(option,
                                           path,
                                           index,
-                                          config_bag)
+                                          cconfig_bag)
                     child.setattr(value,
                                   option_bag,
                                   _commit=False)
@@ -978,16 +973,18 @@ class MetaConfig(GroupConfig):
                                    ' cannot be set together'))
             opt = self.cfgimpl_get_description().impl_get_opt_by_path(path)
             for child in self._impl_children:
+                cconfig_bag = config_bag.copy()
+                cconfig_bag.context = child
                 subconfig, name = child.cfgimpl_get_home_by_path(path,
-                                                                 config_bag)
+                                                                 cconfig_bag)
                 option = subconfig.cfgimpl_get_description().impl_getchild(name,
-                                                                           config_bag,
+                                                                           cconfig_bag,
                                                                            child)
                 option_bag = OptionBag()
                 option_bag.set_option(option,
                                       path,
                                       index,
-                                      config_bag)
+                                      cconfig_bag)
                 if force_default_if_same:
                     if not child.cfgimpl_get_values()._p_.hasvalue(path):
                         child_value = undefined