It's limitations of the e-ink technology. Ever notice certain page turns are slower? They do a "fast refresh" 5 times, and then on the 6th page turn they do a "

It's limitations of the e-ink technology. Ever notice certain page turns are slower? They do a "fast refresh" 5 times, and then on the 6th page turn they do a "full refresh" of the screen to blank the slate and remove any ghosting left from the previous 5 times. Well, I think they have to do the "full refresh" when you're navigating menus. It's been getting better with each generation of Kindle.