T60p, audio issues

[furrycute]

Using the headphone out, occasionally the sound when playing music or movies will have some kind of high pitched noise mixed in the regular audio. This goes away if I stop the music/movie and then replay it, or if I shut down the music/movie player, and then restart it.

Does this sound like a hardware issue or a software issue to you guys?

I am running Vista Ultimate. Haven't done anything drastic changes other than installing MS Office and Adobe Creative Suite on this machine.