Too many aliases?
It is back up and running now, and resolving to the same address it was last night (when it failed). However, last night there were five CNAME records in the chain :-
www.samsung.com. 0 IN CNAME www.samsung.com.edgekey.net.
www.samsung.com.edgekey.net. 2616 IN CNAME www.samsung.com.akadns.net.
www.samsung.com.akadns.net. 4 IN CNAME china-www.samsung.com.edgekey.net.
china-www.samsung.com.edgekey.net. 7998 IN CNAME china-www.samsung.com.edgekey.net.globalredir.akadns.net.
china-www.samsung.com.edgekey.net.globalredir.akadns.net. 117 IN CNAME e1722.g.akamaiedge.net.
e1722.g.akamaiedge.net. 12 IN A 104.72.168.26
Whereas this morning there are only three :-
www.samsung.com. 60 IN CNAME www.samsung.com.edgekey.net.
www.samsung.com.edgekey.net. 9367 IN CNAME www.samsung.com.edgekey.net.globalredir.akadns.net.
www.samsung.com.edgekey.net.globalredir.akadns.net. 1998 IN CNAME e1722.g.akamaiedge.net.
e1722.g.akamaiedge.net. 11 IN A 104.72.168.26
I think that's a smoking gun.
Still, it's bloody stupid having SmartHub depend on www.samsung.com or even an Internet connection - I have an app that provides nice access to content on my local media server - the missus was not happy that that was unavailable too.