Hmm... this is strange. Since about 30 minutes ago, I've not been able to play any of my downloads, even within Napster. I just says 'Opening media' which I think means it's checking that the license is valid.

Could just be a temporary glitch with their service. Or maybe the servers are overloaded because everyone is using this trick (it's on the major sites like News.com now). Or maybe they've stopped all authorisations until they try to fix it!

Edit - seems to be working again