I had the same problem with my 3GS. If you are using a third party cable this is most likely your problem. I took my phone to the apple store and discribed the problem, they said that the new software is not recognizing the cable. I bought an apple composite cable and adapted a car cig ligther power source. Problem sloved! Now I can play music and watch my music/other videos. Looks like apple is trying to keep sales of their products high. Hope this helps.