Your DNS is screwed

One of your listed nameservers (w3c2.w3.org) has no record for www.w3.org.
This means that www.w3.org may, like Schroedinger's cat, randomly
exist or not exist for visitors.

I suggest an urgent fix.

-- 
Nick Kew

Site Valet - the mark of Quality on the Web.
<URL:http://valet.webthing.com/>