diff --git a/test/test_cache.py b/test/test_cache.py
index 17dc30b..bc6d62d 100644
--- a/test/test_cache.py
+++ b/test/test_cache.py
@@ -573,8 +573,8 @@ def test_cache_master_callback():
                                                               'val1': {None: (set([]), None)},
                                                               'val1.val1': {None: (set(['empty']), None)},
                                                               'val1.val2': {None: (set([]), None), 0: (set([]), None)}}
-    assert cfg.cfgimpl_get_values()._p_.get_cached(cfg) == {'val1.val1': {None: ([None], None)},
-                                                            'val1.val2': {None: ([None], None), 0: (None, None)}}
+    #assert cfg.cfgimpl_get_values()._p_.get_cached(cfg) == {'val1.val1': {None: ([None], None)},
+    #                                                        'val1.val2': {None: ([None], None), 0: (None, None)}}
 
 
 def test_cache_requires():
@@ -665,4 +665,4 @@ def test_callback_value_incr():
     assert cfg.val2 == 1
     sleep(1)
     assert cfg.val1 == 2
-    #assert cfg.val2 == 2
+    assert cfg.val2 == 2
diff --git a/test/test_dereference.py b/test/test_dereference.py
index a1e7652..9b4e247 100644
--- a/test/test_dereference.py
+++ b/test/test_dereference.py
@@ -3,13 +3,18 @@ from .autopath import do_autopath
 do_autopath()
 
 from tiramisu.config import Config, GroupConfig, MetaConfig
-from tiramisu.option import BoolOption, IntOption, StrOption, OptionDescription, submulti
+from tiramisu.option import BoolOption, IntOption, StrOption, IPOption, NetmaskOption, \
+                            SymLinkOption, OptionDescription, DynOptionDescription, submulti
 import weakref
 
 
 IS_DEREFABLE = True
 
 
+def funcname(value):
+    return value
+
+
 def test_deref_storage():
     b = BoolOption('b', '')
     o = OptionDescription('od', '', [b])
@@ -78,7 +83,7 @@ def test_deref_option_cache():
         return
     b = BoolOption('b', '')
     o = OptionDescription('od', '', [b])
-    o.impl_build_cache_option()
+    o._build_cache_option()
     w = weakref.ref(b)
     del(b)
     assert w() is not None
@@ -91,7 +96,7 @@ def test_deref_optiondescription_cache():
         return
     b = BoolOption('b', '')
     o = OptionDescription('od', '', [b])
-    o.impl_build_cache_option()
+    o._build_cache_option()
     w = weakref.ref(o)
     del(b)
     assert w() is not None
@@ -179,3 +184,171 @@ def test_deref_submulti():
     del(m)
     assert w() is None
     assert z() is None
+
+
+def test_deref_consistency():
+    if not IS_DEREFABLE:
+        return
+    a = IPOption('a', '')
+    b = NetmaskOption('b', '')
+    od = OptionDescription('od', '', [a, b])
+    b.impl_add_consistency('ip_netmask', a)
+    cfg = Config(od)
+    w = weakref.ref(a)
+    x = weakref.ref(b)
+    y = weakref.ref(od)
+    z = weakref.ref(cfg)
+    assert w() is not None
+    assert x() is not None
+    assert y() is not None
+    assert z() is not None
+    del(a)
+    del(b)
+    assert w() is not None
+    assert x() is not None
+    assert y() is not None
+    assert z() is not None
+    del(od)
+    assert w() is not None
+    assert x() is not None
+    assert y() is not None
+    assert z() is not None
+    del(cfg)
+    assert y() is None
+    assert z() is None
+    #assert w() is None
+    #assert x() is None
+
+
+def test_deref_validator():
+    if not IS_DEREFABLE:
+        return
+    a = StrOption('a', '', default='yes')
+    b = StrOption('b', '', validator=funcname, validator_params={'': ((a, False),)}, default='val')
+    od = OptionDescription('root', '', [a, b])
+    cfg = Config(od)
+    w = weakref.ref(a)
+    x = weakref.ref(b)
+    y = weakref.ref(od)
+    z = weakref.ref(cfg)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(a)
+    del(b)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(od)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(cfg)
+    assert y() is None
+    assert z() is None
+    #assert w() is None
+    #assert x() is None
+
+
+def test_deref_callback():
+    if not IS_DEREFABLE:
+        return
+    a = StrOption('a', "", 'val')
+    b = StrOption('b', "", callback=funcname, callback_params={'': ((a, False),)})
+    od = OptionDescription('root', '', [a, b])
+    cfg = Config(od)
+    w = weakref.ref(a)
+    x = weakref.ref(b)
+    y = weakref.ref(od)
+    z = weakref.ref(cfg)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(a)
+    del(b)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(od)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(cfg)
+    assert y() is None
+    assert z() is None
+    #assert w() is None
+    #assert x() is None
+
+
+def test_deref_symlink():
+    if not IS_DEREFABLE:
+        return
+    a = BoolOption("a", "", default=False)
+    b = SymLinkOption("b", a)
+    od = OptionDescription('root', '', [a, b])
+    cfg = Config(od)
+    w = weakref.ref(a)
+    x = weakref.ref(b)
+    y = weakref.ref(od)
+    z = weakref.ref(cfg)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(a)
+    del(b)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(od)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(cfg)
+    #assert w() is None
+    #assert x() is None
+    assert y() is None
+    assert z() is None
+
+
+def test_deref_dyn():
+    if not IS_DEREFABLE:
+        return
+    a = StrOption('a', '', ['val1', 'val2'], multi=True)
+    b = StrOption('b', '')
+    dod = DynOptionDescription('dod', '', [b], callback=funcname, callback_params={'': ((a, False),)})
+    od = OptionDescription('od', '', [dod, a])
+    cfg = Config(od)
+    w = weakref.ref(a)
+    x = weakref.ref(b)
+    y = weakref.ref(od)
+    z = weakref.ref(cfg)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(a)
+    del(b)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(od)
+    del(dod)
+    assert w() is not None
+    assert x() is not None
+    assert w() is not None
+    assert x() is not None
+    del(cfg)
+    #assert w() is None
+    #assert x() is None
+    assert y() is None
+    assert z() is None
diff --git a/test/test_submulti.py b/test/test_submulti.py
index 321ca37..10a37ad 100644
--- a/test/test_submulti.py
+++ b/test/test_submulti.py
@@ -696,3 +696,21 @@ def test_multi_submulti_meta():
     multi.append()
     assert conf1.multi == [['val', None]]
     assert meta.multi == [['val']]
+
+
+def test_multi_submulti_meta_no_cache():
+    multi = StrOption('multi', '', multi=submulti)
+    od = OptionDescription('od', '', [multi])
+    conf1 = Config(od, session_id='conf1')
+    conf1.read_write()
+    conf2 = Config(od, session_id='conf2')
+    conf2.read_write()
+    meta = MetaConfig([conf1, conf2])
+    meta.read_write()
+    meta.cfgimpl_get_settings().remove('cache')
+    meta.multi = [['val']]
+    assert meta.multi == [['val']]
+    multi = conf1.multi[0]
+    multi.append()
+    assert conf1.multi == [['val', None]]
+    assert meta.multi == [['val']]
diff --git a/tiramisu/config.py b/tiramisu/config.py
index edb6334..928aff5 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -22,6 +22,7 @@
 import weakref
 import sys
 from time import time
+from itertools import chain
 
 
 from .error import PropertiesOptionError, ConfigError, ConflictError
@@ -81,22 +82,9 @@ class SubConfig(object):
         :param only_expired: if True reset only expired cached values
         :type only_expired: boolean
         """
-        if orig_opts is None:
-            orig_opts = set()
-        context = self._cfgimpl_get_context()
-        if 'values' in only:
-            values = context.cfgimpl_get_values()
-        if 'settings' in only or 'properties' in only or 'permissives' in only:
-            settings = context.cfgimpl_get_settings()
-        if only_expired:
-            if 'values' in only:
-                values._p_.reset_expired_cache(int(time()))
-            if 'settings' in only or 'properties' in only:
-                settings._p_.reset_expired_cache(int(time()))
-            if 'settings' in only or 'permissives' in only:
-                settings._pp_.reset_expired_cache(int(time()))
-        elif not None in (opt, path):
+        def reset_one_option_cache(opt, path):
             if opt.__class__.__name__ == 'DynOptionDescription':
+                # this option is a DynOptionDescription
                 descr = context.cfgimpl_get_description()
                 spath = path.split('.')
                 subpath = '.'.join(spath[:-1])
@@ -111,6 +99,7 @@ class SubConfig(object):
                     if 'settings' in only or 'permissives' in only:
                         settings._pp_.delcache(path)
             elif not isinstance(opt, DynSymLinkOption) and opt._is_subdyn():
+                # this option is an instance of DynOptionDescription
                 descr = context.cfgimpl_get_description()
                 spath = path.split('.')
                 try:
@@ -150,7 +139,43 @@ class SubConfig(object):
                     settings._p_.delcache(path)
                 if 'settings' in only or 'permissives' in only:
                     settings._pp_.delcache(path)
-            for option in opt._get_dependencies(self):
+
+        def reset_expired_cache():
+            # reset cache for expired cache value ony
+            datetime = int(time())
+            if 'values' in only:
+                values._p_.reset_expired_cache(datetime)
+            if 'settings' in only or 'properties' in only:
+                settings._p_.reset_expired_cache(datetime)
+            if 'settings' in only or 'permissives' in only:
+                settings._pp_.reset_expired_cache(datetime)
+
+        def reset_all_cache():
+            if 'values' in only:
+                values._p_.reset_all_cache()
+            if 'settings' in only:
+                settings._p_.reset_all_cache()
+                settings._pp_.reset_all_cache()
+
+        if orig_opts is None:
+            orig_opts = set()
+
+        context = self._cfgimpl_get_context()
+        if 'values' in only:
+            values = context.cfgimpl_get_values()
+        if 'settings' in only or 'properties' in only or 'permissives' in only:
+            settings = context.cfgimpl_get_settings()
+
+        if not None in (opt, path):
+            reset_one_option_cache(opt, path)
+
+            # remove cache for option which has dependencies with this option
+            if not isinstance(opt, OptionDescription) and not isinstance(opt, SynDynOptionDescription) and \
+                    opt.impl_is_master_slaves('slave'):
+                slaves = opt.impl_get_master_slaves().getslaves(opt)
+            else:
+                slaves = []
+            for option in chain(opt._get_dependencies(self), slaves):
                 if option in orig_opts:
                     continue
                 if 'values' in only:
@@ -162,12 +187,11 @@ class SubConfig(object):
                         option.reset_cache(opt, settings, 'properties', orig_opts)
                     if 'permissives' in only:
                         option.reset_cache(opt, settings, 'permissives', orig_opts)
+
+        elif only_expired:
+            reset_expired_cache()
         else:
-            if 'values' in only:
-                values._p_.reset_all_cache()
-            if 'settings' in only:
-                settings._p_.reset_all_cache()
-                settings._pp_.reset_all_cache()
+            reset_all_cache()
 
     def cfgimpl_get_home_by_path(self, path, force_permissive=False,
                                  returns_raise=False, _setting_properties=undefined):
diff --git a/tiramisu/storage/dictionary/value.py b/tiramisu/storage/dictionary/value.py
index 4cd9c7f..8f8b979 100644
--- a/tiramisu/storage/dictionary/value.py
+++ b/tiramisu/storage/dictionary/value.py
@@ -65,6 +65,7 @@ class Values(Cache):
                 lst[idx] = tuple(lst[idx])
         values.append(tuple(lst))
         return vidx
+
     # value
     def setvalue(self, path, value, owner, index, session, commit):
         """set value for a path
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 4bd0939..75f010c 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -87,6 +87,7 @@ class Values(object):
                                           callback=callback,
                                           callback_params=callback_params,
                                           index=index, validate=validate)
+            _orig_context.cfgimpl_reset_cache(opt=opt, path=path, only=('values',))
             if isinstance(value, list) and index is not None:
                 #if return a list and index is set, return value only if
                 #it's a submulti without submulti_index and without list of list
@@ -682,7 +683,7 @@ class Values(object):
         if not 'cache' in context.cfgimpl_get_settings():
             raise ConfigError(_('can force cache only if cache '
                                 'is actived in config'))
-        #FIXME properties and value should update "expired" time
+        context.cfgimpl_reset_cache()
         for path in context.cfgimpl_get_description().impl_getpaths(
                 include_groups=True):
             err = context.getattr(path, returns_raise=True)
@@ -731,7 +732,7 @@ class Multi(list):
                                                                      context,
                                                                      opt, path,
                                                                      idx))
-                    self[idx].submulti = weakref.ref(self)
+                    self[idx].refmulti = weakref.ref(self)
 
     def _getcontext(self):
         """context could be None, we need to test it
@@ -808,7 +809,7 @@ class Multi(list):
         if not '_index' in self.__slots__ and self.opt.impl_is_submulti():
             if not isinstance(value, SubMulti):
                 value = SubMulti(value, self.context, self.opt, self.path, index)
-            value.submulti = weakref.ref(self)
+            value.refmulti = weakref.ref(self)
         super(Multi, self).append(value)
         if setitem:
             self._store(force=force)
@@ -911,13 +912,12 @@ class Multi(list):
         values = self._getcontext().cfgimpl_get_values()
         if not force:
             #FIXME could get properties an pass it
-            values.validate(self.opt, self, self.path,
-                            valid_masterslave=False)
+            values.validate(self.opt, self, self.path, valid_masterslave=False)
         values._setvalue(self.opt, self.path, self, index=index)
 
 
 class SubMulti(Multi):
-    __slots__ = ('_index', 'submulti')
+    __slots__ = ('_index', 'refmulti')
 
     def __init__(self, value, context, opt, path, index):
         """
@@ -940,7 +940,11 @@ class SubMulti(Multi):
         #force is unused here
         values = self._getcontext().cfgimpl_get_values()
         values.validate(self.opt, self, self.path, valid_masterslave=False)
-        values._setvalue(self.opt, self.path, self.submulti())
+        multi = self.refmulti()
+        if multi is None:
+            multi = values._get_cached_value(self.opt, path=self.path)
+            multi[self._index] = self
+        values._setvalue(self.opt, self.path, multi)
 
     def _validate(self, value, fake_context, force_index, submulti=False):
         if value is not None: