just plugged in my new i-20 digital dock and disapointed to find a slight popping or cracking auidible during the quieter parts of various tunes. Only seems to happen when playing using my iPhone 4, my iPod classic plays without any problems at all. I'm using the analogue outputs and have tried the phone in airplane mode but it made no difference. Anybody come across and hopefully solved the same problem? Thanks, Dave.........