There is a faint buzzing sound emanating from the bottom of the right speaker when I'm gaming in Windows 7 x64. It doesn't subside when I mute the speakers but when I press down on the part from where the sound seems to be emanating, it goes away, although it retains when I relieve the pressure. What could be malfunctioning? Thanks! I am using a pre-unibody Early 2008 MBP.