Weird... How about a hard reset?
According to sony:
WARNING: A hard reset will erase all content on the Reader.
1. Power off the Reader.
2. On the bottom edge of the Reader, using the stylus, press the RESET button.
3. Turn on the Reader.
4. While the screen displays Opening book... , simultaneously press and hold down the down arrow of the directional button and the 0 button until the Reset All screen is displayed.
NOTE: If Opening book... does not display on the screen, charge the Reader's battery for several hours before attempting the reset process again.
5. Press the 5 button to reset the Reader.