Welcome to Android Central! What do you mean by a forced restart? Are you saying that if you press the Power button to put the screen to sleep, it actually powers off? And then you have to press and hold the Power button again to power back on?
When it powers off, do you see a message that the tablet is powering off? If so, I'd wonder if there's something wrong with the Power button, where it's too sensitive, or registering too long a press despite your only tapping it briefly. If you just let the screen go to sleep on its own (i.e., after the screen timeout), does the tablet still power off?