blossman said Mine does the exact same thing and I was wondering if it had something to do with a firmware update or if it is just a defective unit. When I try to turn it off, it simply reboots instead of powering down. Also, if it is in standby, when I wake it back up it reboots as soon as I have swiped to unlock it. Do you have any updates on yours?

So far the only method I have found that worked for me was this:

1) Google and download an app called Wake Lock.
2) Check the Partial_Wake_Lock option
3) Check Start on Boot option.

after doing this the app will run in hte background and prevent it from rebooting. My tablet had less battery life with this fix so yours might too. I contacted Arnova about this problem and the solution a long time ago but they didnt reply. I think it was a software problem involving the drivers or some other code thing.