I just recently wanted to update my iphone 4 firmware from 4.3.3 to 4.3.5. However every time i try to back up or restore it It give me this message: "Iphone cannot be synced/backedup because a session could not be started with the iphone". And i have tried restoring it in DFU and even re-installed a newer version of itunes (10.5) . Can anyone help me?