Oh joy. As if BT hadn't made things horrid to begin with, with outages sporadically over the past few weeks, it seems something has gone awry again today.
Unfortunately, whilst the primary hpHosts server seems to be working, the rest are not, nor is the mail server (has a motherboard issue). I've done what I can from here, but won't actually have direct access to the servers until later this morning.
My apologies for the downtime folks.