Thats exactly what i was thinking too right now.
My domain is on godaddy where I placed their nameservers:
ns4.urlhasbeenblocked.net, ns5.urlhasbeenblocked.net, ns6.urlhasbeenblocked.net, ns7.urlhasbeenblocked.net.
Then on the urlhasbeenblocked DNS Manager site, I just right now entered a zone with my 'domain' and tied it to one of the IPs.
Not sure where else i should set it up. Based on my personal desktop, I was able to ping my domain without an issue, but am not sure if the vps is able to ping out.
Looks like a DNS failure. Can you ping any of those hostnames? If not, make sure your nameservers are setup properly.