The big problem seems to be the "gapless playback" function at the beginning - if you quit out of that immediately on startup (hit command-period), all should be well. Mine kept freezing up while trying to scan through my whole playlist. Too many songs from too many sources, and the whole thing just stuck. But I'm sure there'll be bug fixes on the way, because just scanning around on the 'Net, I'm seeing a lot of disgruntlement. Apple's gonna have to repair this one pronto.