diff --git a/CHANGES b/CHANGES
index a7da519f18..24ce33f287 100644
--- a/CHANGES
+++ b/CHANGES
@@ -32,6 +32,16 @@ CHANGES
     _with_invoke_all_eagers()
     which selects old/new behavior [ticket:2213]
 
+  - Fixed regression from 0.6 where Session.add()
+    against an object which contained None in a
+    collection would raise an internal exception.
+    Reverted this to 0.6's behavior which is to 
+    accept the None but obviously nothing is
+    persisted.  Ideally, collections with None 
+    present or on append() should at least emit a 
+    warning, which is being considered for 0.8.
+    [ticket:2205]
+
   - Fixed regression from 0.6 where a get history
     operation on some relationship() based attributes
     would fail when a lazyload would emit; this could 
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py
index c721519488..a24348c860 100644
--- a/lib/sqlalchemy/orm/attributes.py
+++ b/lib/sqlalchemy/orm/attributes.py
@@ -722,8 +722,12 @@ class CollectionAttributeImpl(AttributeImpl):
         if self.key in state.committed_state:
             original = state.committed_state[self.key]
             if original is not NO_VALUE:
-                current_states = [(instance_state(c), c) for c in current]
-                original_states = [(instance_state(c), c) for c in original]
+                current_states = [((c is not None) and 
+                                    instance_state(c) or None, c) 
+                                    for c in current]
+                original_states = [((c is not None) and 
+                                    instance_state(c) or None, c) 
+                                    for c in original]
 
                 current_set = dict(current_states)
                 original_set = dict(original_states)
@@ -1114,8 +1118,13 @@ class History(tuple):
         elif original is _NO_HISTORY:
             return cls((), list(current), ())
         else:
-            current_states = [(instance_state(c), c) for c in current]
-            original_states = [(instance_state(c), c) for c in original]
+
+            current_states = [((c is not None) and instance_state(c) or None, c) 
+                                for c in current 
+                                ]
+            original_states = [((c is not None) and instance_state(c) or None, c) 
+                                for c in original 
+                                ]
 
             current_set = dict(current_states)
             original_set = dict(original_states)
diff --git a/lib/sqlalchemy/orm/properties.py b/lib/sqlalchemy/orm/properties.py
index e7f473b675..494d94bb02 100644
--- a/lib/sqlalchemy/orm/properties.py
+++ b/lib/sqlalchemy/orm/properties.py
@@ -818,6 +818,13 @@ class RelationshipProperty(StrategizedProperty):
             if instance_state in visited_states:
                 continue
 
+            if c is None:
+                # would like to emit a warning here, but
+                # would not be consistent with collection.append(None)
+                # current behavior of silently skipping.
+                # see [ticket:2229]
+                continue
+
             instance_dict = attributes.instance_dict(c)
 
             if halt_on and halt_on(instance_state):
diff --git a/test/orm/test_cascade.py b/test/orm/test_cascade.py
index 8c741f0a37..0ff30f906e 100644
--- a/test/orm/test_cascade.py
+++ b/test/orm/test_cascade.py
@@ -307,6 +307,64 @@ class O2MCascadeDeleteOrphanTest(fixtures.MappedTest):
         assert users.count().scalar() == 1
         assert orders.count().scalar() == 0
 
+class O2MCascadeTest(fixtures.MappedTest):
+    run_inserts = None
+
+    @classmethod
+    def define_tables(cls, metadata):
+        Table('users', metadata,
+              Column('id', Integer, primary_key=True, test_needs_autoincrement=True),
+              Column('name', String(30), nullable=False),
+        )
+        Table('addresses', metadata,
+              Column('id', Integer, primary_key=True, test_needs_autoincrement=True),
+              Column('user_id', Integer, ForeignKey('users.id')),
+              Column('email_address', String(50), nullable=False),
+        )
+
+    @classmethod
+    def setup_classes(cls):
+        class User(cls.Comparable):
+            pass
+        class Address(cls.Comparable):
+            pass
+
+    @classmethod
+    def setup_mappers(cls):
+        users, User, Address, addresses = (
+                    cls.tables.users, cls.classes.User, 
+                    cls.classes.Address, cls.tables.addresses)
+
+        mapper(Address, addresses)
+        mapper(User, users, properties={
+           'addresses':relationship(Address, backref="user"),
+
+        })
+
+    def test_none_skipped_assignment(self):
+        # [ticket:2229] proposes warning/raising on None
+        # for 0.8
+        User, Address = self.classes.User, self.classes.Address
+        s = Session()
+        u1 = User(addresses=[None])
+        s.add(u1)
+        eq_(u1.addresses, [None])
+        s.commit()
+        eq_(u1.addresses, [])
+
+    def test_none_skipped_append(self):
+        # [ticket:2229] proposes warning/raising on None
+        # for 0.8
+        User, Address = self.classes.User, self.classes.Address
+        s = Session()
+
+        u1 = User()
+        s.add(u1)
+        u1.addresses.append(None)
+        eq_(u1.addresses, [None])
+        s.commit()
+        eq_(u1.addresses, [])
+
 class O2MCascadeDeleteNoOrphanTest(fixtures.MappedTest):
     run_inserts = None