So here's the deal... When I hit play on iTunes, there is always a delay of about 5-10 seconds of no sound before the track starts playing. It also affects video in browsers, but the behavior is a little different there. The video will start to play without sound. It will play for about 5-10 seconds, at which point the picture will stop, the sound will start (The first 10 seconds of audio that was skipped) until the sound catches up and the entire thing will resume in sync. This has been going on for months. I'm running ML and I believe it happened with Lion too. Safari and Chrome are both affected. I've made a few hardware changes but nothing has changed. What the heck can possibly be going on? It's driving me nuts!