title: Reference to an object magically disaprears? STRANGE
body: <p><strong>EDIT:</strong> Okay, found the answer. Problem was in constructor creating objects that were subject to this bug. It should be doing a deep copy of a prototype object, but in one place was doing copy of <strong>references</strong> in an array instead of copying <strong>whole elements</strong> to newly created object.</p>
  
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  <p>In my C# application I have a <code>Parallel.For</code> loop. In this loop I am creating some object, and calling some method on it. Every loop iteration has <strong>its own objects</strong>, so it is not a problem with one iteration destroying (somehow) object so other iteration can't use it.</p>
  
  <p>I get sometimes (in some not-first iteration of loop) an exception telling one field of my object is null. BUT, when setting debugger on line throwing this exception in Visual Studio C# 2010 when I hover mouse over line (pic rel)</p>
  
  <pre><code>EnvManager MyEnv = Owner.EnvManager;
  </code></pre>
  
  <p>debugger says that Owner.EnvManager object is OK (not null).</p>
  
  <p>BUT, one line below, when comparing MyEnv (assigned just before) to null it is null!</p>
  
  <p><strong>DEBUGGER IS STOPPED ON EXCEPTION THROWING LINE WHOLE TIME, I AM NOT MOVING PROGRAM EXECUTION WHILE CHECKING IT.</strong></p>
  
  <p>Just one question: HOW?</p>
  
  <p><img src="https://i.stack.imgur.com/BKwJE.png" alt="pic showing the problem"></p>