Yslow will not recognise my telerik CDN hostnames

Question

Anyone had a problem getting YSlow to score CDN properly with MS or Telerik static content?

For me it actually says it's using my hostname preferences but then lists them all as components not on CDN. This is what I get:-

Grade F on Use a Content Delivery Network (CDN)

There are 61 static components that are not on CDN.

Using these CDN hostnames from your preferences: aspnet-scripts.telerikstatic.com , ajax.microsoft.com , aspnet-skins.telerikstatic.com , http://aspnet-skins.telerikstatic.com, telerikstatic.com

http://aspnet-skins.telerikstatic.com/ajaxz/2010.3.1109/Menu.css

http://aspnet-skins.telerikstatic.com/ajaxz/2010.3.1109/Black/Menu.Black.css

http://aspnet-skins.telerikstatic.com/ajaxz/2010.3.1109/Ajax.css

http://aspnet-skins.telerikstatic.com/ajaxz/2010.3.1109/Sitefinity/Ajax.Sitefinity.css

http://aspnet-skins.telerikstatic.com/ajaxz/2010.3.1109/ComboBox.css

http://ajax.microsoft.com/ajax/4.0/1/MicrosoftAjaxWebForms.js

http://aspnet-scripts.telerikstatic.com/ajaxz/2010.3.1109/Common/Core.js

http://aspnet-scripts.telerikstatic.com/ajaxz/2010.3.1109/Ajax/Ajax.js

etc...

I've tried to cover the angles withe the CDN name qualification but Yslow keeps contradicting itself and doesn't actually accept any combination of the hostnames - unless of course I'm being stupid and missing something obvious here!

edit Sorry I didn't make it clear in OP that I've followed the Yslow FAQ - "Add my CDN hostname to YSlow for Rule 2" advice. http://developer.yahoo.com/yslow/faq.html#faq_cdn

Answer 1

In the end I removed and reinstalled Firefox 3.6.13, firebug 1.6 and YSlow 2.1 and now it works - very odd.

I may have installed Yslow and firebug addins in the wrong order before - perhaps that caused the problem.

Answer 2

This is covered in the YSlow FAQ - you can add custom hostnames to the list of CDNs. See "How do I add my CDN hostname to YSlow for Rule 2?" for more details.