title: ASP.NET authentication cookie disappears, only in IE, only from specific locations
body: <p>Internet explorer is not keeping my authentication cookie after one page redirect. </p>
  
  <p>Here is the situation:</p>
  
  <p>I have an ASP.NET 2.0 web application running on a shared iis7 hosting. The application uses forms authentication to handle login and user identity and writing a cookie (.ASPXFORMSAUTH) on the client machine for that purpose. </p>
  
  <p>in IE (checked with version 8, 9), <strong>from some locations</strong>, the authentication cookie is not being kept after the first page. The observed behavior is:</p>
  
  <ol>
  <li>User name and password are submitted in login form</li>
  <li>User is succesfuly redirected to the first-after-login page (and fiddler shows that the .ASPXFORMSAUTH cookie exists)</li>
  <li>After clicking another link or hitting F5 for refresh, the user is credirected to login, and the authentication cookie (according to fiddler) doesn't exist anymore. 
  at the refresh / click, the authentication cookie is missing in the request headers. </li>
  </ol>
  
  <p>This doesn't happen in Chrome / FF, and even in IE, it seems to be dependent on the location from which I am connected. </p>
  
  <p>also, locally (using the internal dev server in VS2008), all works fine and reflects fine in fiddler as well. </p>
  
  <p>I am banging my head at it for a few days now. Thought it may be some kind of a strange firewall problem, but couldn't determine anything conclusive. </p>
  
  <p>Ideas will be appreciated. </p>