[solved] Webpage has expired issue#

In IE7, if I click a result in the results page, let that page load and then click the browser's back button to return to the list of results then I get the following message:

Webpage has expired

Most likely cause: The local copy of this webpage is out of date, and the website requires that you download it again.
What you can try: Click on the Refresh button on the toolbar to reload the page. After refreshing, you might need to navigate to the specific webpage again, or re-enter information.

Does anyone know how can I avoid this?

I've managed to find a fix for this which I hope might be of use to someone else.

I added a snippet to the top of the Template for the search results which adds this:

<?
header( 'Cache-Control: private, max-age=10800, pre-check=10800' );
?>

Seems to work for me.

Thanks for that, fixed for me too (IE.

Brilliant!

Fixed my issue.

<?php
header( 'Cache-Control: private, max-age=10800, pre-check=10800' );
?>

More thanks for this solution.

The same error was reported by one of my users today. Strange that the site has been live for 2 years, but it hasn't been reported before. No changes to MODx that would affect this, but maybe something PHP/Apache was changed on the server?

I put the code into a MODx snippet, so it only sets the Cache-Control header for the search page.