title: Fluent NHibernate SqlDateTime overflow exception
body: <p>I'm mapping a very simple Users table, and i have a column named 'LastLoginDate' which is defined as nullable in sql server.</p>
  
  <p>My mapping looks like this :</p>
  
  <pre><code>public Users {
      Id(x =&gt; x.UserId);
      Map(x =&gt; x.UserName);
      ...
      ...
      Map(x =&gt; x.LastLoginDate).Nullable();
  }
  </code></pre>
  
  <p>But everytime I try to save this entity programatically, i always get the SqlDateTime overflow exception.
  If i try to enter a manual sql statement with 'null' in this column it works.
  If i comment out just this property, it will work as well.</p>
  
  <p>What can be the problem ???</p>
  
  <p>Thanks in advance!</p>