I am a novice and have installed W3 Total Cache. I watched videos and read posts on which settings were best to select for my site. As far as I can tell I have enabled all browser caching options, yet when I run speed tests (gtmetrix and pingdom), they give me an 'F' in the "leverage browser caching" category. There are other categories that need work as well, but this one comes up failing on all of my pages, not just ones with many images--though the problem I am seeing via gtmetrix involves the caching of images. Any tips would be appreciated. My domain is http://www.truthincharity.com. I am using twenty-eleven with the latest version of wordpress.