Power up the Device while holding the black button located in the front of the device and menu. Let go of the menu+Black button at the same time after the screen shows up. I had this problem yesterday and Figured it out.
This is what is now happening with my device.
I was just pressing buttons when I noticed this...
When I get the green communication.. powered by wowpad screen, if i then hold the black back button with the menu button, after a few seconds in the middle of the screen in blue text says the words "KERNAL PANIC" and the Pad restarts.
If that helps anyone solve the problem...
Sorry, I should have been more clear. My pad restarts back to the green screen of death then hangs again