You can try installing the
recovery package. Copy the "OS Firmware" folder onto the micro-SD card, insert the card into the reader. Reset the reader (push the RESET hole with a pin). Turn the reader on while holding HOME and MENU keys. Continue pushing both keys until the "Opening book..." bar is about half way through. The screen should show "Updating", wait till it says it's done (may take a while). Reset again, this time letting it boot into the Normal mode. Most of the time it does help.
Good luck!