Thanks for the detailed description of your resolution to the hibernation/ sleep problems you have had. For those with more general questions related to sleep, hibernation and hybrid sleep setting check out this information: http://windows.microsoft.com/en-us/windows7/Sleep-and-hibernation-frequently-asked-questions.
Have Windows & on two PC, a Built AMD and a Dell laptop.
Many folks are having problems with Windows 7 Sleep and Hibernation,
My problems were that both machines would enter sleep and shutdown for hibernation but never wake. Just a black screen.
Sadly, many of these problems are MACHINE SPECIFIC.
For the Dell Laptop ,I carefully reconfigured the advanced settings.
Turned off hybrid sleep and USB suspend. and It woke up.
(I need to do more test with the Dell cuz it's not mine)
For my built AMD again MACHINE SPECIFIC, I think many people with these problems are like me builders so read close.
Windows 7 seems picky about RAM TIMINGS.
NOT ram SPEED like DDR800 but the actual TIMINGS.
My whole system is overclocked(most everything) so I was getting sad and thinking that Windows 7 wants me to keep stock speeds.
But after many different things, I found that returning the ram back to stock timings everything was fine.
CPU and RAM are still overclocked but I have relaxed the ram to 188.8.131.52 from 184.108.40.206 damn, but now she wakes up.