I recently noticed my powerbook is making a high pitched whine. It seems to be coming from the speakers and the volume control has no effect. If I scroll with the track pad or if the hard drive is accessed it seems to stop briefly. If I go into the Energy Saver Preference and set the processor to reduced the whine stops. Automatic and Highest both produce the whine. I do not know what it could be since my powerbook g4 was recently in for service and was repaired by apple. It recently updated two drivers so (Yamaha Keyboard and Griffin Scroll Wheel Thing) i'll see if it is that. Does any one have any ideas? Thanks!