I regulary have an extremely annoying squeaky electronic sound coming from itunes when playing music. It sits over the top of any track played through itunes. It won't discriminate between music purchased online or music imported from disc. I have a 1.8Ghz G5 iMac running OS X 10.4.11 with all updates installed, 2gb ram and plenty of free space. I'm running my itunes library from an external hard drive but have the noise issue with tracks played locally. All music copied to ipods, burnt etc. will play without the sound, only through itunes???? I have deleted all music out of itunes and re-imported. I have just splashed out on a very expensive set of headphones and all I can hear is an electronic squealing bird in them!!!!! Any suggestions?