New W520 hibernation problem

[EHL]

Want to know if anyone else has seen this problem.

Last night, before I went to bed, I had my new W520 hibernated.
I was really surprised to find that the W520 was running this morning. After logging in, there was a window in the middle of the screen saying Bluetooth PIM service was updated and needed to be configured. I do have a bluetooth mouse nearby but it was turned off after I put the machine into hibernation.

So can a laptop, or any computer for this matter, wake up from hibernation without being touched? Is this a problem of the W520 or I missed something about Hibernation?

Any ideas? Any one?

[EHL]

On a second thought, this behavior may be caused by the settings of the computer. May be it was in a hybrid mode of sleep and hibernation, maybe the "wake on lan" setting is on. I will check on these settings when I get home today to make sure it won't happen again.