Not that anyone will be as relieved as me, or even interested, but turned out the extension cable in USB1 was just not connected properly - as predicted.

Love this unit. Wife is starting to get a bit jealous.

Something unexpected (to me at least) happened today as well - bluetooth music streaming kicked in from my phone in my pocket (despite smartphone being set to USB). Happened after my wife unplugged her phone from USB2.

Tremendous. Anyway - thanks for previous replies!