Working for me at the moment on Kapiti cable. Note that the address doesn't ping so I'm guessing they are blocking ICMP traffic. Note that the transparent proxy issue wouldn't show itself with pings as the two are unrelated.
Next time something like this happens I find it useful to try https rather than http. It isn't, of course, enabled on all sites but if that works and http doesn't, then that points to the transparent proxy. Otherwise if that isn't working either then either the site doesn't have https or its not the transparent proxy - you'll have to use your best guess which one :)