Leverage Browser Caching not working

Installed the plugin and results are positive except for the leverage browser cache.
No results in GT Metrix. Anyone any idea on how to make it happen?

All settings have been checked and seems to be fine, even the .htaccess file has been modified by W3 Cache.
Website is running on a VPS Apache/Linux server single wordpress installation.
http://www.outdoorplazaxl.nl

Looking forward to any contribution..
Regards,
André

http://wordpress.org/plugins/w3-total-cache/