When I see the apps running in the background in multitasking, every app has some sort of screenshot. Well, my ipad mini retina sometimes has apps in the multitasking displaying images that happened weeks ago. For example if I visit mac rumors on safari, double press home button to see the safari app, it shows mac rumors. Now if I close the safari app from the multitasking and than open safari again multiple times, everything is normal. After a few weeks, in multitasking, safari will show the mac rumors website opened a few weeks ago. I don't know if you really understand this but it happens even when I kill the app from the multitasking tray. I am on 7.1.2 non jailbroken.