I was using my ibooks then suddenly it restart the when I open ibooks again it goes back to previous page.... I cant open any ibooks pdfs it shuts and goes back...
If you aren't and you've got books on your device, sync with iTunes. Right-click on your device in the left-hand column of iTunes and select, 'Transfer Purchases' - This should sync your books across to your iTunes (that's if you've bought them from iTunes).