DNS servers, what is going on today?

I use Open DNS, yet several times today I have the 404 error "Server not found" or whatever and then I get a page stating ClearCloud DNS is shutting down. Happened trying to log into here once too. Anyone else experiencing this? Thank you!
I'm editing: My router's Tomato firmware GUI has three DNS fields. My third choice, after the two Open DNS servers may have been ClearCloud. I've replaced it with Google's.

 

I also use OpenDNS and I did not encounter those broken pages.

 

Could it be from a DDOS attack? EasyDNS was under attack a couple of days ago:

http://blog.easydns.org/2012/01/09/post-mortem-of-the-jan-07-ddos-attack/

 

Could have been, although I did check OpenDNS site earlier and there isn't any mention of it. I've replaced the third server field with Googles 8.8.8.8! If I don't have anymore errors I'll presume it was that my third was a ClearCloud.

 

@ratchet
What browser do you use?

 

Ff 9.0.1
Also, no problems since I added Google's server as a third option!

 

Clearcloud doesn't do public DNS anymore so if your router was bypassing OpenDNS, that would have prevented resolutions. Clearcloud is now only offered for using the Vipre security suite. This was as of Sept last year but their website says it went into effect a few days ago.

www.clearclouddns.com