I run a Wordpress site & use W3 Total Cache. I’ve used this to set up a CDN using Rackspace Cloud Files. When running tests on the site there’s just a big ‘X’ on the CDN detected mark.
Is the tester detecting my CDN or have I missed an option or something in W3 Total Cache?
Since posting I’ve changed to Amazon Cloudfront in case Rackspace was the problem. The two PNG’s are hosted on the CDN so I’m not sure yet why they’re being served by my server, and I’ve since found I can’t select the ‘Host minified CSS and JS files’ option in the CDN section of W3TC, still working on that problem.
Do you have a link to the results? What CDN are you using? WebPagetest knows about a lot of CDNs but not necessarily all of them so it could just be an issue of you using a CDN we’re not aware of.