I have Amazon kindle for my Iphone and downloaded the app to my Ipad. On the Ipad it told me I had to register the device. So...over to Amazon and it did have my Iphone registered but I got caught in some sort of loop. It seems that I have to de-register the Iphone, but if I do I can't use that account ever again (thus losing the books I have there). Can't I register the Ipad version too? Anyone with any experience of this?