With last update of Grooveshark, keySharky 1.5 is temporally broken, because new shiny HTML Grooveshark doesn’t yet ship with GroovesharkAPI (should be fixed in next week as I was told).

But if you can’t wait that long and still want to use Grooveshark that knows how to talk with keySharky you could upgrade to keySharky 1.5.1 for Firefox (not yet reviewed so no automatic update available) or/and Prism. After upgrade go to http://retro.grooveshark.com/ and you should be fine till GroovesharkAPI is added to new shiny version. That’s all :)