volumeone.org
UPDATE
It's been more than 10 days now, and DNS changes still haven't been updated for some people using AT&T (but since 4 days ago, it's showing up for at least one AT&T user that it wasn't before).
Updated DNS to point to a new IP address (switched a server within the same host).
People are seeing the new website almost everywhere, but several people are still not seeing the new site after 6 days. I am one of them. My home AT&T connection is not updated and at least one other person that reported this also uses AT&T.
I checked with the hosting company (softlayer) and they confirmed that the DNS settings are configured correctly. They said there's nothing I can do but change the TTL and wait.
OpenDNS also has not updated the IP address for their New York and Washington DC locations, according to this page. (sometimes it shows the correct IP addresses, sometimes it doesn't)
http://cachecheck.opendns.com/
I've never seen this before. Does anyone have any suggestions?
Best Answer
The nameservers appear to be somewhat less than optimally set up. Looking at the output from DNSCheck for volumeone.org, there are a few things that stand out.
The two name servers are both on the same AS. This means that if there is any problem reaching that AS, then neither of your nameservers will be accessible. It's generally recommended to have name server in at least two separate netblocks with separate routing, preferably in separate server halls, to avoid this.
SOA refresh and retry times are a bit low.
Apart from that, I can only suggest that you contact AT&T DNS admins. Possibly your hosting provider would be able to get in touch with them directly; I would assume that they're not easy for an end customer to get hold of.