Hi, My white macbook is having a sound output problem. I'm using very long (10 meters) cable - it's a Profigold PGA3402 minijack to phono. (http://www.profigoldcables.co.uk/catalog/product_info.php?products_id=29) The first thing I've noticed is the electric shocks I'm getting when the minijack is plugged in (when touching the "phono" ends). Any possible explanation of why this is happening? I turned down the amp and connected it to the macbook and discovered that only one channel is working. When I plugged the headphones in - there was no sound at all. I tried this cable with my mp3 player and it works without any problems - so I can assume that its the Macbook problem but before calling Apple I want to see if anyone experienced anything similiar? Thank you!