As a current user of the new client you should have recievd an email explaining the need for a reinstall yesterday. Did you not recieve this? The problem was that we detected a major bug in our database which required some drastic measures. In practice what this means for you is the filter client needs to rescan your music collection, and the only way to do this currently is to reinstall the application on your machine. We looked at the alternatives, and this impacted least on our system, and is a once only event. Apologies for disrupting the service, it's essential we fixed this problem before we went live to the wider public.