I'm using Windows 7 64-bit and Ubuntu . My hosts file is empty. I'm using Firefox and Internet Explorer.
When I tried to visit some sites I get a Server Not Found error. If I refresh the page a few times, it's working.
However some sites (for example cloudfront.net) aren't working outright.
I have also tried it with OpenDNS with the same result, and on two different locations.
What do you think the problem might be, and how could I fix it?