Every once in a while, seemingly at random (could be playing a game, browsing the internet, sometimes just after start-up) I will hear a short burst of buzzing (not static) from my speakers. This happens for a second or two, stops for a second or two, and then starts again. Also, at the same time the buzzing is happening, my whole computer will stutter....the mouse will jump, the display will stutter, the whole computer seems to quickly freeze and unfreeze for a second or two, then be fine, then stutter again. Basically it makes it unusable. The only "cure" Ive found so far is to just restart the computer, and it usually goes away. Any ideas?