"there is a back up problem, make sure the destination drive or device is connected then try again"

Norton Security | Norton Internet Security
1

Hello,

 

I'm running Windows  7 and have Norton 360 version 5.0, I've created the initial back successfully but I always get the above message when trying to run a back up after that.  I've checked the drives are turned on, connected and live, checked the back up rules and drive designations against the back up "rules" and still get this message. What is the problem?!