jarledb:myopinion:
Primary: 208.122.23.22
Secondary: 208.122.23.23
That did not work here. Taking Unblockus off of the DNS setup on the iPad did work though. So it is Unblockus that messes up the service.
One option would be to set the unblockus dns on your router at home for only those sites that you need unblockus for - I do this mine on an ASUS RT-AC66U with dd-wrt tomato flashed on it and it works great. Doesn't work for away from home and you would then need to manually set the dns for it in that situation or, as I do, use a VPN when accessing outside my local network at home.

