Everybody was absolutely right--the issues I was having were to do with the TV subscriptions and Digital Voice handsets not being activated (and legacy phone wire still there). Fine now: only took two engineer visits and rather a lot of support calls to fix.
Next question: the Humax box had a tidy little gauge at the bottom showing how much storage is free/used. How would I get this? I intend to clear things once watched apart from a few I'd keep, but it'd be good just to keep an eye on it.
