Hello HarryT,
I followed your advice, and left it charging overnight. But the problem persists.
The strips appear and disappear randomly (apparently), and always horizontally. If I switch the viewing mode (using the accelerometer), the stripes do not change orientation.
Sometimes, though not as frequently, the letters in the book look like they are slightly faded.
I attempted to update the firmware. No success. Formatting the device has shown no progress, as well.
I hope this is not a hardware issue...
