WP Super Cache is an amazing Wordpress plugin for webmasters with large sites or with sites that use a ton of SQL queries to generate the content. When I first installed, everything appeared to be working fine. When I tested the site in Internet Explorer 7 I received the dreaded “Explorer cannot display the webpage” error. There where a couple of things that I needed to change in order to make it work. The first thing was that I had to modify the “/wp-content/cache/.htaccess” file.

Add the following code at the beginning of the htaccess file directly below the “# BEGIN WPSuperCache”

<IfModule mod_mime.c>
AddEncoding gzip .gz
AddType text/html .gz
</IfModule>
<IfModule mod_deflate.c>
SetEnvIfNoCase Request_URI \.gz$ no-gzip
</IfModule>
<IfModule mod_headers.c>
Header set Cache-Control 'max-age=300, must-revalidate'
</IfModule>
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType text/html A300
</IfModule>

This seemed to fix some bugs I was having with IE6, but IE7 still wouldn’t display the page. I then realized that earlier I had started using PHP gZip compression. So at the top of the header.php file for my theme I had the following line.

ob_start("ob_gzhandler");

Once I removed this then IE7 displayed the page right away.