I'm using microsoft's CDN for pulling down the Ajax libraries. And I'm using SSL on some pages.
This URL resolves fine in Firefox and IE:
https://ajax.microsoft.com/ajax/4.0/MicrosoftAjax.js
However in google chrome (on my PC, today...) it seems to time out with a very odd response:
On other PCs it seems to work fine, however I know I'm not the only one experiencing the problem as we've had occasional complaints from some of our clients about certain pages timing out and failing, that seems to point to the same problem.
As per my comment, I experienced the same issue but with Firefox failing and Chrome and IE succeeding.
Restarting the browser and the computer had no affect. Clearing the browser cache did fix the issue. I can only assume there was some kind of corruption in the browser cache.