My MBP i5 starts over when the bettery finishes!!

[iGOOGLE]

Hi guys
please help me with this matter.

every time the battery finishes, when I press the power button, the system starts over.
it never starts as I was working on before!

Is there any settings should i do in the preferences?
I tried to find but I couldn't.

 

[deadwulfe]

This is purely speculation, but when was the last time you calibrated your battery? I'm guessing it thinks it has enough power left to go into hibernation, but it really doesn't, so it ends up just powering off before hibernation gets a chance to kick in.