Try this trick to update the firmware:
http://www.youtube.com/watch?v=wa8i_bDAm5Y
Turn the unit on, then turn it back off. When you turn it off, keep holding the power button down. Then hold the thumb stick in the up position at the same time, and update the system software from your computer. While it's updating, keep the power down held down and the thumb stick held in the up position. Once the update is complete, you can release the buttons.