After 9 months of trying to run this down, installing and reinstalling Windows 7, updating drivers
etc. I finally solved a problem I have been having with Windows 7 crashing when resuming from sleep mode. Hopefully this will help others.
The problem I had showed in the Event Viewer as a Kernel Power Error and the symptoms were, when resuming from sleep, that the screen would slowly (every few seconds) cycle from black then back to showing the desktop / open windows. The cursor would also be mostly non-responsive and the taskbar background would be black when the screen was on. Also, a video driver
error message would pop up in the notifications area at the bottom of the screen. Ultimately I would have to do a hard re-boot by pressing and holding the power button. The Event Viewer error message referred to the video driver atikmdag.
My machine is a core 2 duo Toshiba A300-ST4004 laptop with an ATI Radeon Mobility HD3650 video card. SOLUTION (actually - a work-around)
: by minimizing all active windows (i.e., showing the desktop) before putting the machine into "sleep" mode, my system now sleeps / resumes from sleep without any issues or crashing. Seems unbelievable that something so simple would work, but it does. System has been stable for over 48 hours without a crash.
I hope this helps others.