My kindle has frozen up on me twice in the past three days....screen freezes, none of the buttons or cursor will work, and even when I turn it off the page I was reading stays right there. Both times I have used the reset button in the back of the kindle and after a few minutes the kindle turns off and then seems normal when I turn it on again. But I have never ever had to do a reset before so twice in less than a week is freaking me out a bit. Is this in the normal range? How often do others have to reset I am asking because my one year warranty on the kindle is up in two more weeks so this is making me extremely nervous.