I've got an iphone 4 and two docking towers that I use to charge/play music etc. Everything was fine until the other day when I went to go use one of the towers and a message popped up saying 'accessory not supported by iphone', so I tried to use my other one and the same message popped up. This has never happened before with either of the docks and now it's happening to both. My brother's ipod works fine. I have tried everything, from turning both my phone and the docks off and on again, cleaning out all the dust from my phone properly and cleaning the docks. NOTHING WORKS. My phone is fully updated, although I doubt it has anything to do with the update because I've used the docks since then and it has been fine. I am really at the end of my tether with this so if anyone can help me I will be so happy, thanks.