My wife has an iPad 1, with os 5.1. Right now there are no movies loaded, no music videos and no videos in the photo section, but it shows over 7 gb of memory taken up by video! On the unit itself under usage for video it says "no data." Synchs occur without issue, but always show the seven gb taken by video. Can't backup because there isn't enough memory left on the unit. Please help! Thanks in advance.