My Mac pro must not like XP. Last night, when I booted into XP (boot camp) it started making a very high pitched whine. the sound is coming through the speakers but it not affected by any soundcard settings. It sounds like some type of feedback or ??? I tried rebooting a few times and it's always there now. OSX is just fine but when ever I boot into XP, there is a very high frequency -EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE- noise. Any thoughts?