Yep someone broke it yesterday it seems. I doubt this is a coincidence:
Domain Name: NTLWORLD.COM
Registry Domain ID:
Registrar WHOIS Server: whois.networksolutions.com
Registrar URL:
http://networksolutions.com
Updated Date: 2014-08-25T00:00:00Z
There do not appear to be any authoritative DNS servers for the domain right now.
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 61013
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;ntlworld.com. IN A
;; AUTHORITY SECTION:
com. 512 IN SOA a.gtld-servers.net. nstld.verisi gn-grs.com. 1409056395 1800 900 604800 86400
;; Query time: 24 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Tue Aug 26 13:40:57 BST 2014
;; MSG SIZE rcvd: 114
I presume it's also been fixed but is taking time to propagate around the interwebs as DNS does.