This has happened to both my Samsung Galaxy Tab 2 7.0 and Galaxy Player 4.2. The Amazon Kindle android app doesn't seem to recognize some of the ebooks in my Kindle library. When I email a personal document to my Kindle Library, the document doesn't show up on my Galaxy device, but it does on my iPod Touch. On my Galaxy device, I have to de-register and re-register my device before the document will show up. This is a pain because after de-registering and re-registering, I have to re-download all my ebooks from my Kindle library to my Galaxy device. Has anyone experienced this? Has anyone experienced this on non-Samsung Galaxy android devices?