Have done as you suggested and done repair permissions but still have the problem - and have tried to select a singer, then a song from their album and it's not working. If I select playlists and select one of my playlists I just get the choice of choosing again rather than it showing whats in the playlist.
In case it may have a baring on what's wrong - I've downloaded the Evernote workflow and that's not working either (I'm in contact with Carlos about this). Other workflows Weather, Alfredtweet and Search Mail (all by David Ferguson) seem to be working fine.