hi folks. i've recently noticed the audio from my 1st gen. white macbook's headphone out has a short echo on all audio (itunes, web, movies). it is not present with same headphones/diff. source (ipod), and the sound is fine from itunes to my stereo via optical out (which i used for a long time) or via my airport express (which i've recently switched to). i hear it with all my different headphones. i've also just upgraded to leopard. i'm not sure if this was happening before in tiger or not. it's subtle but noticable - especially when you stop the audio - the echo remains for a split second - it's obvious compared to stopping the audio listening though the airport. bass and treble also seem messed up a bit but i'm less sure of that. anyone heard of such thing? thought i'd ask before i go to the apple store and compare. thanks - matt.