why does my Bose docking station not work with my iPhone4?

purchased a Bose series II docking station. had it returned because it wouldn't play anything from my iPhone 4 iOS 5.1. new one came, and still, no sound from my dock. Tried it with an iPod and had not problems, but I purchased it to play all my music, not just 8igs of it. is there an intentional block in the update to restrict certain products, or is this all happening by chance? I waited for a newer update that 5.1 and 5.1.1 didn't solve my problem. any advice, or insight that I'm lacking would be greatly appreciated. thanx. Ben