title: Why my aspx page is being requested from cache on my dev machine only
body: <p>Ok - so I am testing a web application and am getting some strange behaviour on my development box that I can't work out.  The same behaviour is not exhibited on a colleagues machine.</p>
  
  <p>The issue is as follows:  I am making two requests to index.aspx.  The first request comes back as a HTTP 200 (as I would expect), but the second request is retrieved from browser cache.  I am clearing the cache at the start of each test to ensure the tests are consistent.  I am also using a utility called HTTPWatch (a lot like fiddler, but shows requests even if they are retrieved from browser cache) which shows me HTTP information and this is how I know it is coming from the cache.</p>
  
  <p>The issue only occurs on one of my machines.</p>
  
  <p><strong>Colleagues Machine (Works fine)</strong></p>
  
  <ul>
  <li>Request is sent to index.aspx
  <ul>
  <li>Headers Sent:
  <ul>
  <li><strong>(Request-Line):</strong> GET /index.aspx HTTP/1.1</li>
  <li><strong>Accept:</strong> text/html, application/xhtml+xml, <em>/</em></li>
  <li><strong>Accept-Encoding:</strong> gzip, deflate</li>
  <li><strong>Accept-Language:</strong> en-GB</li>
  <li><strong>Connection:</strong> Keep-Alive</li>
  <li><strong>Cookie:</strong> (Not relevant)</li>
  <li><strong>Host:</strong> dev</li>
  <li><strong>User-Agent:</strong> Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)</li>
  </ul></li>
  <li>Headers received:
  <ul>
  <li><strong>(Status-Line):</strong> HTTP/1.1 200 OK</li>
  <li><strong>Cache-Control:</strong> private</li>
  <li><strong>Content-Length:</strong> 10369</li>
  <li><strong>Content-Type:</strong> text/html; charset=utf-8</li>
  <li><strong>Date:</strong> Wed, 08 Feb 2012 09:09:38 GMT</li>
  <li><strong>Server:</strong> Microsoft-IIS/7.5</li>
  <li><strong>X-AspNet-Version:</strong> 2.0.50727</li>
  <li><strong>X-Powered-By:</strong> ASP.NET</li>
  </ul></li>
  </ul></li>
  <li>Second Request Sent to index.aspx
  <ul>
  <li>Headers Sent:
  <ul>
  <li><strong>(Request-Line):</strong> GET /index.aspx HTTP/1.1</li>
  <li><strong>Accept:</strong> text/html, application/xhtml+xml, <em>/</em></li>
  <li><strong>Accept-Encoding:</strong> gzip, deflate</li>
  <li><strong>Accept-Language:</strong> en-GB</li>
  <li><strong>Connection:</strong> Keep-Alive</li>
  <li><strong>Cookie:</strong> (Not relevant)</li>
  <li><strong>Host:</strong> dev</li>
  <li><strong>Referer:</strong> <a href="http://dev/index.aspx" rel="nofollow">http://dev/index.aspx</a></li>
  <li><strong>User-Agent:</strong> Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)</li>
  </ul></li>
  <li>Headers received:
  <ul>
  <li><strong>(Status-Line):</strong> HTTP/1.1 200 OK</li>
  <li><strong>Cache-Control:</strong> private</li>
  <li><strong>Content-Length:</strong> 33588</li>
  <li><strong>Content-Type:</strong> text/html; charset=utf-8</li>
  <li><strong>Date:</strong> Wed, 08 Feb 2012 09:09:38 GMT</li>
  <li><strong>Server:</strong> Microsoft-IIS/7.5</li>
  <li><strong>X-AspNet-Version:</strong> 2.0.50727</li>
  <li><strong>X-Powered-By:</strong> ASP.NET</li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p><strong>My Machine (Doesn't work)</strong></p>
  
  <ul>
  <li>Request is sent to index.aspx
  <ul>
  <li>Headers Sent:
  <ul>
  <li><strong>(Request-Line):</strong> GET /index.aspx HTTP/1.1</li>
  <li><strong>Accept:</strong> application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, <em>/</em></li>
  <li><strong>Accept-Encoding:</strong> gzip, deflate</li>
  <li><strong>Accept-Language:</strong> en-GB</li>
  <li><strong>Connection:</strong> Keep-Alive</li>
  <li><strong>Cookie:</strong> (Not relevant)</li>
  <li><strong>Host:</strong> dev</li>
  <li><strong>User-Agent:</strong> Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)</li>
  </ul></li>
  <li>Headers received:
  <ul>
  <li><strong>(Status-Line):</strong> HTTP/1.1 200 OK</li>
  <li><strong>Cache-Control:</strong> private</li>
  <li><strong>Content-Length:</strong> 10374</li>
  <li><strong>Content-Type:</strong> text/html; charset=utf-8</li>
  <li><strong>Date:</strong> Wed, 08 Feb 2012 09:45:304GMT</li>
  <li><strong>X-Powered-By:</strong> ASP.NET</li>
  </ul></li>
  </ul></li>
  <li>Second Request Sent to index.aspx
  <ul>
  <li>Headers Sent:
  <ul>
  <li><strong>(None):</strong> No Headers sent for cached items</li>
  </ul></li>
  <li>Headers received:
  <ul>
  <li><strong>(None):</strong> No headers received for cached items</li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>As you may have noticed, the browsers are different (ie8 to ie9), but I still can't see why this would be an issue.  I think it must be some browser configuration as the headers received on the first request are virtually the same.</p>
  
  <p>If anyone can explain why the second request is being retrieved from cache, I would be very grateful.</p>