My Win-7 laptop has issues with both HIBERNATE & sleep enabled. The hot-key default goes to hibernate even though it says sleep.

Coming out of hibernate Windows will reboot & say computer was shutdown improperly. I DISABLED hibernate & use sleep, then change advanced power settings & disable sleep for USB.
https://www.google.com/search?q=windows+7+reboots+after+sleep&ie=UTF-8

Every once in a while, a Windows Update or some other update will re-enable hibernate.
Turn off hibernate with this: http://support.microsoft.com/kb/920730

When this first happened, I thought the battery had drained when it was in sleep. It happened a few more times & I thought the battery must be bad. Then it started happening with the new battery, then it happened while plugged into the AC ADAPTER, so started searching for a cure.

I bought an HP laptop about 2 1/2 months ago. I just enabled hibernate today, setting the computer to hibernate when I press the power button, and tested it. No problem. I use the same setting with an old HP Compaq d530CMT Pentium 4 desktop system I'm using with Windows 7. Both computers go into sleep mode after a set time. Since he's been ABDUCTED apparently...we may never know.