[Freebooter]

Open the Command Prompt as a administrator and type Powercfg /LASTWAKE this command reports information about what woke the system from the last sleep transition.

[Freebooter]

Try the "Powercfg /LASTWAKE" command after Windows wake up from hibernation.
Also open the Event Viewer by typing eventvwr.msc into Search charm and see if there is any logs indicating what cause the Windows wake from hibernation or sleep.

[Freebooter]

It doens't wake up when I unplug either.

There's a bunch of stuff in the event viewer but nothing mentions anything about hibernation or sleep.

Open the Event Viewer and expand "Windows Logs" then click on the 'System' event log.
Right-click, and then choose "Filter Current Log".
Input the event id 1 number into input box above the "Task category" input box.
In the "Event sources" window, click the drop-down and put a check-mark beside "Power-Troubleshooter" and then click "OK.
You will see listing of wake & sleep events and look at the the "General" tab at the very bottom for each wake events the wake source will be shown it will be display at the "Wake Source: " entry.

[img]http://cdn3.mos.techradar.futurecdn.net//Review%20images/PC%20Plus/PCP%20304/PCP304.make6.customview-580-90.jpg[/img]

[Freebooter]

Open the "Control Panel --> Power Options" click “Change plan settings” for each power scheme and click “Change advanced power settings” in the next section and expand the entry called “Sleep” as well as its submenu “Allow wake timers” set all to “Disable”. This will stop scheduled automatic wake up of the computer.
Also type powercfg /devicequery wake_armed to list devices that are currently configured to wake the system from any sleep state.

[Tweekzify]

Mate, did you fix the problem? Cuz i have the EXACT same problem.. I can be ALMOST to sleep, and then i hear my computer starting lol! Ive tried to put mouse upside down and everything ^^

[Freebooter]

You can disable the devices from waking your computer by typing powercfg /devicedisablewake "<DEVICENAME>" replace the <DEVICENAME> with the device name that is retrieved using powercfg /devicequery wake_armed command.