I have the same problem. I have used iTunes for years with no problems. When I installed v10.5.3, it constantly froze. I uninstalled and reinstalled with spotty success and then next time I turn on the computer--freezes again. Today I installed 10.6 and the same thing is happening. If I go into my iTunes library, I can play one song at a time! I am ready to convert all to mp3s and use a different player.