I need understanding on this: Notice: PHP caching enabled but Supercache mod_rewrite rules detected

Hi,
I need bettter understanding on this not on my WP admin in WP Super Cache setting stating this:

Notice: PHP caching enabled but Supercache mod_rewrite rules detected. Cached files will be served using those rules. If your site is working ok please ignore this message or you can edit the .htaccess file in the root of your install and remove the SuperCache rules.

Now, due to this, my site that is fairly fast is now crawling like snail and sincerely I'm lost here because the test stamp of WPSuper Cache says ok but site still load and this not refused to go.

How can I solve this?

Secondly, how can I register, use, configure CDN for cache plugin like WP totalcache or WP Super cache?
url: http://sportvisionng.com

Regards