OK, but when did this error occur? If you had a couple of weeks ago, it was "normal" because there had been issues with the domain. But if you mean today, it's strange, because everything works now. At least, nobody else reported troubles.
And if it was today, did you try adding google DNS to your network settings?
8.8.8.8
8.8.4.4
I'm also find very, very good the OpenDNS
208.67.222.222
208.67.220.220