Since Sept 2008, this X200 has entered hibernation flawlessly, whether running Vista or 7. Starting about two weeks ago, and no, I'm not aware of any changes made at that time, here's what happens when attempting to enter hibernation:
1. Laptop monitor goes dark
2. Hibernation file (hiberfil.sys) is created (I made sure by deleting it, then attempted to enter hibernation)/modified
3. The "moon" light in the monitor bezel does NOT light as it should
4. If you wait a period of time sufficient for the laptop to enter hibernation, then move the Trackpoint or press keyboard keys, the monitor illuminates and displays the logon screen as though you've locked the computer/come out of sleep mode.
1. From an elevated command prompt, I've run "powercfg -h on" and toggled it back and forth.
2. Reset to default the settings in my power plan (for testing purposes, I'm using the built-in Balanced plan.)
Any clue? Thank you so much for helping.