title: #pragma warning is not suppressing a warning
body: <p>One of my .cpp files is generating warning C4275 due to a 3rd-party header I <code>#include</code>... (the warning is triggered due to a DLL-export class inheriting from a non-DLL-export class as far as I can tell).</p>
  
  <p>I added the line:</p>
  
  <pre><code>#pragma warning(disable : 4275)
  </code></pre>
  
  <p>As the first line of my .cpp file and yet the warning is still being generated. This is on VC++ 2008, and no PCH is in use.</p>
  
  <p>Why is my <code>#pragma</code> not working, and (other than changing the 3rd-party code) how can I address this?</p>