i experience the following problem. from time to time the speakers make a very very anoying sound, very bad for the ears scratching which is intolerable. it is not cause of the loudspeakers, cause i've tried with my headphones and still the same problem. i changed the audio card with a card from a friend of mine and still the same thing. i change the pci slot of the audio card and still the same... i try to mute some of the settings and yet... nothing is change. can u tell me what kind of problem is this, i think it is not software, so probably there is some interefearance with the hardware. what shall i do?