After two years of beta, Google released mod_pagespeed from beta.
Google has said that website speed performance impacts search engine ranking results, however there are dozens of factors for many web sites via a variety of platforms. This new update automates many of Google’s web optimization recommendations.
Unfortunately this server module can cause minor conflicts for third party software such as WordPress and some e-commerce software. The most common conflict I’ve seen is with WordPress; specifically that the visual editor in the WordPress dashboard disappears when editing existing posts.
To fix this, add this line to your .htaccess file.
You can also disable mod_pagespeed all together, by adding this line to your .htaccess file.