I turned my external drive on, let it be for a short time, and looked in the finder window only to notice that time machine appeared to still be backing up! So I opened my System Preferences, and into the time machine settings. The progress bar just seemed to be stuck on "Preparing" and not really going anywhere. So I stopped it, restarted the computer, and retried the backup... Guess what? Same thing happened. Its still just stuck on "Preparing". Can anybody help me please?