Why is one installation of IE8 (unexpectedly) loading pages from cache, while others are not?

I have website that is ASP.NET with Forms Authentication, clicking the logout button does correctly call FormsAuthenication.SignOut() so it invalidates the cookie.

All machines in the office are using IE8 and work fine, just like Firefox. But one installation of IE8 will load cached copies of authenticated pages even after logging out when navigating using links on the pages instead of automatically being redirected to the login.aspx for attempting to reach a secured resource.

If th开发者_C百科ey attempt to do any postback or refresh the page it will correctly redirect them but I don't understand why this is occuring, I can't reproduce this does anyone else have any idea what could cause and how to stop it?

Try Internet Options->General->Browsing History Settings and make sure that "Check for new versions of stored pages" isn't set to "Never".

The following is probably no longer relevant; just leaving it here for a while for the comments. (And the HTTP response headers might still give some clue.)

Seems to me that IE8 might in fact be working as expected here...

• What do the HTTP response headers say about caching? See, for example, Firebug's "Net" panel in Firefox, or Web Inspector's "Resources" panel in Chrome or Safari.

• Any <meta> tag with caching details?