I have installed Altec Lansing VS2620 speakers. They are good but if I don't move the computer mouse every half hour or so, random loud music blares out from them, like an aural screensaver. This is really irritating if I want to relax and listen to the radio or watch a long TV programme on my PC where I am not using the mouse. Is there a way to turn off this function or at least delay it for a longer time period? Thanks.