public void Test1()
{
    Configuration cfg = new Configuration();

    IDictionary props = new Hashtable();
    props["hibernate.connection.provider"] = "NHibernate.Connection.DriverConnectionProvider";

    props["hibernate.dialect" ] = "NHibernate.Dialect.FirebirdDialect";
    props["hibernate.connection.driver_class" ] = "NHibernate.Driver.FirebirdDriver" ;
    props["hibernate.connection.connection_string"] = "User=SYSDBA;Password=xxx;Database=TestDB.gdb;DataSource=localhost;Port=3050;Dialect=3;Charset=NONE;Role=;Pooling=true;MinPoolSize=0;MaxPoolSize=50;Packet Size=2048;ServerType=0" ;

    foreach( DictionaryEntry de in props )
    {
        cfg.SetProperty( de.Key.ToString(), de.Value.ToString() );
    }

    cfg.AddAssembly("Test");

    ISessionFactory factory = cfg.BuildSessionFactory();
    ISession session = factory.OpenSession();

    try
    {
        ITransaction transaction = session.BeginTransaction();
        try
        {
            if(!session.IsConnected)
            {
                session.Reconnect();
            }

//        Roles newRole = new Roles();
//        newRole.RoleName = "Guest";
//        session.Save(newRole);

            IList roles = session.Find("from Roles as roles where RoleName = "+"'Guest'");

            Users newUser = new Users();
            newUser.UserId = "joe";
            newUser.Password = "123";
            newUser.Role = (Roles) roles[0];
            
            // Tell NHibernate that this object should be saved
            session.Save(newUser);

            // Force an exception to test rollback bug
            throw new Exception("Force it");

            // commit all of the changes to the DB and close the ISession
            transaction.Commit();
        }
        catch (Exception)
        {
             transaction.Rollback();
        }

/*
**  If the next four lines are commented out, Rollback works and user row is not saved
**  But if the next four lines is executed after rollback, an row "joe" will be written to the database
        IList userList = session.CreateCriteria(typeof(Users)).List();
        foreach(Users user in userList)
        {
            string id = user.UserId;
        }
*/
    }
    catch (Exception)
    {
         // do nothing
    }
    finally
    {
        session.Disconnect();
        session.Close();
    }
}