Just got the Iphone5s and I'm trying to set up the finger print security login. I don't know if it's me or the phone, but I can't seem to get it to work. I hold my thumb on the home button and half the time nothing happens, the other half I see it starts to scan my finger and create a partial print. When I feel it vibrate I lift and reapply as instructed, but it never goes anywhere and says it failed to read my prints. My hands are clean and dry. Am I doing something wrong?