Just on the blind offchance it comes with the attachments to turn the power adapter into a UK and US plug, I don't suppose you ended up with a spare US attachment? I shipped my Squeezebox to the US but along the way managed to lose the US adapter, and since I left the UK one behind (knowing it wouldn't work here) I can't even use that and use a socket converter :-(
Funnily enough, my Squeezebox was a grey import that came with only with the US adapter for the adapter, that I adapt with yet another adapter. So I've got the US one but I'm using it.
Did you leave the UK one with relatives that they could send to me, to swap? Alternatively, you or I could use an alternative mains adapter. Any 5V DC 2A+ one will do, with the DC plug or cable changed if necessary.