Hi I am a new Milestone user, I moved from the HTC hero because of this very same problem. I found the mp3s would make strange clipping sounds as if the phone was strugleing to encode the music. It happened on my HTC Hero, too. The exact same fault. After comming from the Iphone3gs I put it down to being spoilt with a great music device. But surely phones with500 Mhz processors can handle it? It happens more when you are moving in a car, but still happens when stationary. I have nothing running in the background.