I'm not sure that we have/had the same problem. The fact that you can get an IP address suggests that it is not a dns problem as cpayne suggested. I couldn't even get that far. You can try ipconfig /flushdns from the cmd window. If not, onlydarksets suggested
OpenDNS > Get Started. That is what did it for me. Also, there are other domain names that you can try but I think you should go to Matty for those.