Enable browser caching of static assets

[jabubo]

Try to add something like this, to an .htaccess file in the root-Folder of your website.

The settings add the expire header for the mime-types (Javascript, CSS, png, jpg and so on) beginning at the time the client access the file and adding the time specified as expiration time.
In the code below A604800, stands for accesstime + 604800 seconds is the expiration time.

In this time the client do not request the content again. Unless the client uses a local cache.

Code:

<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType application/javascript A604800
ExpiresByType application/x-javascript A604800
ExpiresByType text/javascript A604800
ExpiresByType text/css A604800
ExpiresByType image/gif A604800
ExpiresByType image/x-icon A604800
ExpiresByType image/icon A604800
ExpiresByType image/jpg A604800
ExpiresByType image/jpeg A604800
ExpiresByType image/png A604800
</IfModule>

Just check the HTTP-Header of any file mathing this. If the expire-header is not used, your provider has not enabled mod_expires for the Apache webserver. Ask him to do that.