title: Fluent nhibernate : Problems when deleting a HasOne relationship
body: <p>I have two classes </p>
  
  <pre><code>public  PartMap()
  {
     Id(x =&gt; x.ID).GeneratedBy.Guid();
     HasOne(x =&gt; x.Stock)
            .Cascade.All();
  }
  
  public Stock
  {
    Id(x =&gt; x.ID).GeneratedBy.Guid();
    References(x =&gt; x.Part);
  }
  </code></pre>
  
  <p>Part has only one stock, that's the reason i used HasOne.
  The data is inserted ok, I have a part , a stock and they are saved ok.
  My problem is when trying to delete I get an error that the stock foreing key to part was violated</p>
  
  <pre><code>"ORA-02292: integrity constraint (PRINERGY.FK121AD9E59966BE23) violated " .
  </code></pre>
  
  <p>I see the it tries to delete the part without deleting the related stock before.
  How can I solve it?</p>