OK, BT have now looked at it and confirmed that we sync at 36 meg as far as they're concerned.
Having tested all (*) the kit in the house, have passed it firmly back to Zen as a potential routing issue.
The only avenue we haven't explored is this potenial underrated PSU that you mentioned. The neighbours have had 5 new modems so far (I think the dog is eating them) but still have a black PSU - argh.
Networking I'm happy with, electrics less-so. Could you possibly point me towards a suitable higher-rated PSU I could buy and try out, please? If there's no change, pfft we tried. But it's the only thing we haven't had a go at and I like to be thorough. Plus we'd like to go to 80meg when it's available, but if it's overloaded at 40 then 80 ain't gonna help.
Ideally, "go into Maplin and ask for..." or a link to a mail-order site would be lovely
Thank you very much in advance!