I had another go and there was no problem.
http://www.isitdownrightnow.com seems to think it's fine and was last down more than 6 days ago -- try switching to a different DNS if you can, Google's one at 8.8.8.8 is good.
My ISP here in the UK, BT, insists on their equipment only using their DNS and they have taken to messing us about and censoring access to a lot of sites, so I'm aiming to take steps to foil their petty censorship, even if I have to ditch their router in the process. (It doesn't help that the British government has just voted in an emergency bill calling on providers to log and retain for a year all emails and texts, all in the name of the so-called "fight against terrorism"!)
If I was a terrorist I'd be using SSH tunneling, TOR, and/or encryption -- maybe I'll start doing just that to make things much harder for government interference in my privacy even though I haven't got anything to hide!