Use a Titanium G 4 867 with OSX 10.5.8 Leopard. After upgrading to Leopard operating system from Tiger I began having issues with my ITunes glitching out on me. I don't know if this was a coincidence that this started shortly after installing Leopard. More research I do I'm led to think it could be a heat issue. This problem arises when I'm using Youtube as well. There will be times where the sound performs without a problem then suddenly begins to freeze or cut in and out. Use headphones a lot and when this starts happening if I take the headphones out of jack it tends to activate the audio again. This may only be for a brief moment sometimes then it freezes up again. Someone with any ideas or similar problems in the past please let me know. Need to narrow the possibilities.