title: Unable to load configuration file web.config - in use by another process
body: <p>The w3wp.exe process is throwing the following ConfigurationErrorsException:</p>
  
  <p><strong>An error occured loading a configuration file: The process cannot access file file 'web.config' becuase it is being used by another process</strong></p>
  
  <p>Here's what we've determined so far:</p>
  
  <ul>
  <li>The error is intermittant! Sometimes a refresh of the page in the browser is enough to kickstart it again. Sometimes not.  The file is locked enough that we cannot open it using notepad when connected directly on the web server.</li>
  <li>Because of the intermittent appearance of this error, it does not appear to be a file permission issue.</li>
  <li>We have multiple applications under this exact configuration that are having this issue. They are in separate application pools. There have been no changes to the application code around the time that the errors started occuring.</li>
  <li>We cannot find any processes other than the w3wp.exe that are accessing this file.</li>
  <li>Our web application does not write any changes to the web.config file, only reads values from it.</li>
  <li>This error is happening on multiple servers in our web farm</li>
  <li>We cannot replicate this error in our development environment. It only occurs in production.</li>
  <li>The application are running on x64 servers (Win 2008 Server), using the .NET 4.0 Framework. </li>
  </ul>
  
  <p>Ideas?</p>