Hey guys, I've just merged a couple threads on this issue together.
Thanks for flagging this with us. We've let the right folks know and we'll keep you updated here.
Mine is now working on the Squeezebox Radio.
This is what I did:
1 - logged into the box by installing the media server and then going to localhost http://localhost:9000/
2- installed Spotify 3rd Party plugin
3 - set settings for plugin (username and password)
4 - opened up port 9005 on router
5 - changed password on spotify for account
6- removed account from box, re added using new password
7 - everything appeared again!