Lately I have noticed a really high pitched, barely audible ringing coming somewhere from my desk. At first I thought it was my monitor, but after I removed that, I could still hear it. I just noticed now that it's my MX510 mouse. I never noticed the high pitched ringing sound before, but it's there now; especially if I put my ear right up agains the bottom where the light is. Does ne1 else get the very high pitched sound from their mice?