x31: problem of waking up from sleep mode

[lumenite]

Hello,

My old X31 got a new problem recently.
So far I had enjoyed the sleep mode, but now I became afraid of using it.
When I open the lid to wake it up, its power goes out sometimes.
Even when it is plugged, the led of power-connected goes out together.
In order to turn it on again, I have to push power button after removing battery and power cable. and then I connect again and turn on.
Something wrong seriously.
Is there anybody who can help me in any way?
Thank you.

[Puppy]

I had to update BIOS in order to get hibernation work properly.