I'm running MacOSX 10.5.8 on a MacBook Pro.
I was working on my computer last night. I finished work, closed the lid and expected the computer to go to sleep. I assume this is the Apple Safe Sleep mode. My battery was about 70% charged.
Tonight, I open up my laptop and discover that the computer refuses to start and battery has been completely discharged. When I plug the computer in again, all information from my previous session was lost. It's as if the computer shut down completely.
What's happening here? Shouldn't the computer go to sleep and save all information to disk? When I wake the computer up from sleep mode, shouldn't it restore all information from my previous session?
This only happens about 5% of the time that I close the lid. Usually, this works as I expected.
Update to answer @zneak's question:
This is the hardware model, according to About this Mac: More Info...: Hardware
.
Model Name: MacBook Pro
Model Identifier: MacBookPro3,1
MacBookPro6,2
.)