NHibernate one-to-one problem

output.sql

-- statement #1
begin transaction with isolation level: Unspecified

-- statement #2
SELECT bar_.Foo,
       bar_.Rate  as Rate1_,
       bar_.Value as Value1_
FROM   [Bar] bar_
WHERE  bar_.Foo = '2b76e14d-c48e-490d-9d1c-9d0900ee14ec' /* @p0 */

-- statement #3
INSERT INTO [Bar]
           (Rate,
            Value,
            Foo)
VALUES     (5 /* @p0 */,
            10 /* @p1 */,
            '2b76e14d-c48e-490d-9d1c-9d0900ee14ec' /* @p2 */)

-- statement #4
ERROR: 
Could not execute command: INSERT INTO [Bar] (Rate, Value, Foo) VALUES (@p0, @p1, @p2)


-- statement #5
WARN: 
System.Data.SqlClient.SqlException: The INSERT statement conflicted with the FOREIGN KEY constraint "FK52E419EEE5E038AA". The conflict occurred in database "sandbox", table "dbo.Foo", column 'Id'.
The statement has been terminated.
   at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
   at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
   at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
   at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
   at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at NHibernate.AdoNet.AbstractBatcher.ExecuteNonQuery(IDbCommand cmd)
   at NHibernate.AdoNet.NonBatchingBatcher.AddToBatch(IExpectation expectation)
   at NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object id, Object[] fields, Boolean[] notNull, Int32 j, SqlCommandInfo sql, Object obj, ISessionImplementor session)


-- statement #6
ERROR: 
The INSERT statement conflicted with the FOREIGN KEY constraint "FK52E419EEE5E038AA". The conflict occurred in database "sandbox", table "dbo.Foo", column 'Id'.
The statement has been terminated.


-- statement #7
ERROR: 
Could not synchronize database state with session

source.cs

using System;
using System.IO;
using System.Threading;
using FluentNHibernate.Cfg;
using FluentNHibernate.Cfg.Db;
using FluentNHibernate.Mapping;
using NHibernate.Tool.hbm2ddl;

namespace ValueMapping
{
    public class Program
    {
        private static void Main(string[] args)
        {
            HibernatingRhinos.Profiler.Appender.NHibernate.NHibernateProfiler.Initialize();

            if (Directory.Exists("schema"))
                Directory.Delete("schema", true);
            Directory.CreateDirectory("schema");

            var cfg =
                Fluently.Configure()
                    .Database(
                    MsSqlConfiguration.MsSql2005
                        .ConnectionString(x => x.Server(".").Database("sandbox").TrustedConnection())
                        .ProxyFactoryFactory<NHibernate.ByteCode.LinFu.ProxyFactoryFactory>()
                    )
                    .Mappings(x =>
                              x.FluentMappings
                                  .Add<FooMapping>()
                                  .Add<BarMapping>()
                                  .ExportTo("schema"))
                    .BuildConfiguration();

            new SchemaExport(cfg).Drop(false, true);
            new SchemaExport(cfg).Execute(false, true, false);

            var sf = cfg.BuildSessionFactory();

            object id;

            try
            {
                using (var session = sf.OpenSession())
                using (var t = session.BeginTransaction())
                {
                    var f = new Foo();
                    f.Name = "bob";
                    f.Bar = new Bar();
                    f.Bar.Foo = f;
                    f.Bar.Rate = 5;
                    f.Bar.Value = 10;

                    id = session.Save(f);

                    t.Commit();
                }
            }
            finally
            {
                HibernatingRhinos.Profiler.Appender.NHibernate.NHibernateProfiler.Stop();
                Thread.Sleep(1000);
            }
        }
    }

    public class Foo
    {
        public virtual Guid Id { get; set; }
        public virtual string Name { get; set; }
        public virtual Bar Bar { get; set; }

        public virtual bool Equals(Foo other)
        {
            if (ReferenceEquals(null, other)) return false;
            if (ReferenceEquals(this, other)) return true;
            return other.Id.Equals(Id);
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(null, obj)) return false;
            if (ReferenceEquals(this, obj)) return true;
            if (obj.GetType() != typeof (Foo)) return false;
            return Equals((Foo) obj);
        }

        public override int GetHashCode()
        {
            return Id.GetHashCode();
        }
    }

    public class Bar
    {
        public virtual Foo Foo { get; set; }
        public virtual int Value { get; set; }
        public virtual int Rate { get; set; }

        public virtual bool Equals(Bar other)
        {
            if (ReferenceEquals(null, other)) return false;
            if (ReferenceEquals(this, other)) return true;
            return Equals(other.Foo, Foo);
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(null, obj)) return false;
            if (ReferenceEquals(this, obj)) return true;
            if (obj.GetType() != typeof (Bar)) return false;
            return Equals((Bar) obj);
        }

        public override int GetHashCode()
        {
            return Foo.GetHashCode();
        }
    }

    public sealed class FooMapping : ClassMap<Foo>
    {
        public FooMapping()
        {
            Id(x => x.Id).GeneratedBy.GuidComb();
            Map(x => x.Name);
            HasOne(x => x.Bar).Constrained().Cascade.All().ForeignKey("none");
        }
    }

    public sealed class BarMapping : ClassMap<Bar>
    {
        public BarMapping()
        {
            CompositeId().KeyReference(x => x.Foo);
            //Id<Guid>("id").GeneratedBy.Foreign("Foo");
            //HasOne(x => x.Foo).Constrained().ForeignKey();
            Map(x => x.Rate);
            Map(x => x.Value);
        }
    }
}