Just to conclude the thread - I got a replacement adaptor from the fine folks over at PiHut and as soon as that one was plugged into the setup, everything worked - so it was the USB adaptor all along.

Thanks everyone for your help!

No, that's what I mean - I'm not using the adaptor for that, just the Zero. So the USB adaptor appears to be dead.

The image is brand new, it's not an old one. Wiped the card and got the very latest from the site. As noted, the Pi boots to desktop correctly on the Zero, it just doesn't detect any USB peripherials. OK so I found this in the Zero specific thread: Take your Zero, with nothing in any slot or socket ...

I recently bought a RasPi Zero (which was an experience in itself, fighting off the digital throng to snag one) and powered it up at work on Friday. I already have one of the first RasPi Model B units, which I'd used to install 3 different distros with earlier in the week, specifically the newest av...