Nothing to worry about?
Maybe not 'worried' exactly, but not being able to use the Reader in intense sunlight would be a big disappointment. I mean, the use in natural light is one of their main claimed benefits!
To clarify - the letters are not fading with time, they are looking like this right after the page turn.
Someone explained that the effect is supposedly happening at the time of the page turn, not during the static display, and suggested keeping the reader shaded during the page turn. If that was true it's still disappointing, because I don't really want to have to move the Reader into the shade each time I flip the page!
I hope that mine is just one of the 'bad apples' and it can either be adjusted, or exchanged for a better specimen.