I use my custom built notebook to play music over a stereo system and depending on where I set up (other than my home)I usually get annoying interference through the speakers. When I unplug the AC charger and run off the batteries, the noise goes away. Also when I grab the charging block and give it a squeeze the noise gets either worse or better. I have a feeling the charger may just be cheap and is having a grounding issue, but it would be nice to know for sure what the cause is. Sometimes the noise will dissapate if plugged in for awhile. Any thoughts on this would be very welcome.