I followed your blog post regarding performance optimization with W3 total cache. Minifying CSS breaks my layout and I suppose that some css should be excluded. Your blog doesn’t show the images anymore, so it would be very interesting which configuration you chose.
Please try to configure the site based on this option’s screenshot. These are actions that are based on this specific host (our host). So you have to play around with the options and find the right configuration especially for your website. You may need to change the engines to make the minify possible.