How to update the firmware:
1. Extract the archive
2. Plug in your Device
3. Copy the .bin file to your SD-Card
4. Shut down the device
5. Boot the device, while booting hold both big buttons
6. Press Centerbutton, when asked for
7. Wait till device will start again (Otherwise reboot the device manually, or press the reset)
File:
http://pocketbook-global.com/downloa...de_ws_v15_1.7z
Could be that you have to reconfigure your Keys after update.