diff --git a/proteus/__init__.py b/proteus/__init__.py
index ffd9451755..0936522f5f 100644
--- a/proteus/__init__.py
+++ b/proteus/__init__.py
@@ -258,6 +258,8 @@ class Model(object):
 
     def __init__(self, id=None, **kwargs):
         super(Model, self).__init__()
+        if id:
+            assert not kwargs
         self.__id = id or Model.__counter
         if self.__id < 0:
             Model.__counter -= 1
@@ -271,8 +273,15 @@ class Model(object):
         for field_name, value in kwargs.iteritems():
             definition = self._fields[field_name]
             if definition['type'] in ('one2many', 'many2many'):
+                relation = Model.get(definition['relation'])
+                value = [isinstance(x, (int, long)) and relation(x) or x
+                        for x in value]
                 getattr(self, field_name).extend(value)
             else:
+                if (definition['type'] == 'many2one'
+                        and isinstance(value, (int, long))):
+                    relation = Model.get(definition['relation'])
+                    value = relation(value)
                 setattr(self, field_name, value)
     __init__.__doc__ = object.__init__.__doc__
 
@@ -481,7 +490,7 @@ class Model(object):
             res[arg] = scope
         return res
 
-    def _set_on_change(self, field, value):
+    def _on_change_set(self, field, value):
         if self._fields[field]['type'] in ('one2many', 'many2many'):
             if isinstance(value, (list, tuple)):
                 self._values[field] = value
@@ -501,13 +510,13 @@ class Model(object):
                     relation = Model.get(self._fields[field]['relation'],
                             self._config)
                     # append without signal
-                    list.append(getattr(self, field), relation(*vals))
+                    list.append(getattr(self, field), relation(**vals))
                 for vals in value.get('update', []):
                     if 'id' not in vals:
                         continue
                     for record in getattr(self, field):
                         if record.id == vals['id']:
-                            for i, j in vals.iteritems:
+                            for i, j in vals.iteritems():
                                 record._values[i] = j
                                 record._changed.add(i)
         else:
@@ -531,9 +540,9 @@ class Model(object):
                 if self._fields[field]['type'] in ('one2many', 'many2many'):
                     later[field] = value
                     continue
-                self._set_on_change(field, value)
+                self._on_change_set(field, value)
             for field, value in later.iteritems():
-                self._set_on_change(field, value)
+                self._on_change_set(field, value)
             if self._parent:
                 self._parent._changed.add(self._parent_field_name)
         if definition.get('change_default'):
@@ -552,7 +561,7 @@ class Model(object):
             context = self._config.context
             res = getattr(self._proxy, 'on_change_with_%s' % field)(args,
                     context)
-            self._set_on_change(field, res)
+            self._on_change_set(field, res)
 
 
 class Wizard(object):
diff --git a/proteus/tests/test_model.py b/proteus/tests/test_model.py
index fe2d4130c9..a29767e209 100644
--- a/proteus/tests/test_model.py
+++ b/proteus/tests/test_model.py
@@ -79,6 +79,22 @@ class TestModel(TestCase):
         self.assert_(test2.id < 0)
         self.assertNotEqual(test1.id, test2.id)
 
+    def test_init(self):
+        User = Model.get('res.user')
+        self.assertEqual(User(1).id, 1)
+        self.assertEqual(User(name='Foo').name, 'Foo')
+
+        Lang = Model.get('ir.lang')
+        en_US = Lang.find([('code', '=', 'en_US')])[0]
+        self.assertEqual(User(language=en_US).language, en_US)
+        self.assertEqual(User(language=en_US.id).language, en_US)
+
+        Group = Model.get('res.group')
+        groups = Group.find()
+        self.assertEqual(len(User(groups=groups).groups), len(groups))
+        self.assertEqual(len(User(groups=[x.id for x in groups]).groups),
+                len(groups))
+
     def test_save(self):
         User = Model.get('res.user')
         test = User()
@@ -266,3 +282,30 @@ class TestModel(TestCase):
 
         trigger.on_create = True
         self.assertEqual(trigger.on_time, False)
+
+    def test_on_change_set(self):
+        User = Model.get('res.user')
+        Group = Model.get('res.group')
+
+        test = User()
+        test._on_change_set('name', 'Test')
+        self.assertEqual(test.name, 'Test')
+        group_ids = [x.id for x in Group.find()]
+        test._on_change_set('groups', group_ids)
+        self.assertEqual([x.id for x in test.groups], group_ids)
+
+        test._on_change_set('groups', {'remove': [group_ids[0]]})
+        self.assertEqual([x.id for x in test.groups], group_ids[1:])
+
+        test._on_change_set('groups', {'add': [{
+            'name': 'Bar',
+            }]})
+        self.assert_([x for x in test.groups if x.name == 'Bar'])
+
+        test.groups.extend(Group.find())
+        group = test.groups[0]
+        test._on_change_set('groups', {'update': [{
+            'id': group.id,
+            'name': 'Foo',
+            }]})
+        self.assert_([x for x in test.groups if x.name == 'Foo'])