title: Using Linq to Sql, does not update, but does not throw exception
body: <p>Running .net 2008, asp.net, Linq to sql, sql server 2008 express</p>
  
  <pre><code>Foo f = db.Foo.First(x =&gt; x.ID == id);
  f.IsValid = true;
  db.SubmitChanges();
  </code></pre>
  
  <p>I have a very basic table, which has several fields, and no FK constraints.  None of the data saves when I call .SubmitChanges(), but no error is thrown.  Any ideas?</p>
  
  <p>Not using any explicit transaction scope, fields are not autogenerated, and no triggers on the server.</p>