Hello, I have a iphone 3g and a yamaha surround sound system. I purchased the yamaha dock that plugs in to the surround sound receiver several months ago. It worked great with my iphone and my older ipod, until recently. The yamaha dock still works fine with the ipod but when using the iphone there is no sound, if i'm playing a song through the iphone speakers, then plug the phone onto the dock the sound stops from the phones speaker but nothing comes from the yamaha system. I also have a portable sound dock, the iphone still works with that dock so I don't suspect the iphone is faulty, just maybe theres a setting in the phone thats incorrect, I suspect the problem started when the phone was undated but i'm not sure. Thanks for any help.