I just updated my Iphone 3GS to ISO 4.0 and my Itunes to the latest version. every time I plug my IPhone into in it wants to restore my phone, and on top of that it won't sync my music. It's also saying that the required file could not be found and that there was an internal error. There was no error code given though. What do i need to do to fix this? HELP!!!!!! 