Now I know the problem.
WP Super Cache doesn’t support leverage caching on pictures like PNG or JPEG . You have to active the mod_expires.c modul in your root .htaccess file (if your provider supports this).
For Example:
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/png “access plus 5184000 seconds”
</IfModule>
You can try to remove the <IfModule>-Tag in your .htaccess file. Than you try to reach your website. If you get an internal server error, the mod_expires.c module is not supported by your provider.
Best regards
I am sorry, but I forgot a few important information.
The side is http://www.blog-it-solutions.de and the function “Caching” in the plugin “wp-super-cache” is active. I also modified the .htaccess file in the right way. Furthermore I use mod_rewrite for caching the side.
If I try to scale my blog on http://pagespeed.googlelabs.com/ I get the message, that I should active browser caching to improve my website performance. The current result is 53 points of 100.
But I think browser caching is on, because I use the plugin wp-super-cache. Do I make an error in my plugin configuration or is the result on Google Page Speed common?
Best regards
