iPhone iTunes problems

Trying to backup by iPhone in iTunes. I keep received the error "The iPhone software server could not be contacted. The requested resource was not found." I have tried all of Apples suggestions; restarting both my iPhone and my Mac, making sure I have all the most recent updates. Nothing has worked. I have not jailbroken my phone. In fact, it is pretty new as I just bought it about 3 months ago. I have no problems up until now. Any ideas?