I had an iBook G4 1Ghz. I rarely had any problems watching internet videos on sites like Hulu or YouTube. I passed the iBook along to a friend when I got a new MacBook, and he has been unable to watch Web videos. They play, but the audio is ahead of the sound. He's tried it on a few different connections, but they all do this in both Safari 4 and Firefox 3. Clearing the browser cache helped a little, but it hasn't gone away. Does anybody know what's causing this?