QUOTE(munky @ Mar 12 2007, 06:48 PM)

So i'm now convinced that the GPU is hanging on S3 resume, and that this is the cause of my problems.
I think you're right. I've followed this thread while trying to fix S3 sleep on my own box with moderate success, so I thought I should share these results. One observation I made early on is that almost no one in this thread (and the related cpu throttle/sleep thread) is running a Core 2 system and no one has my motherboard or graphics card (see my sig for system profile). In my situation certain bios settings have everything to do with getting this to work. Bare with me...
After installing 10.4.8 sse3 semthex 8.8.1 and getting my audio & lan working plus display modes my first attempt to sleep from the menu bar results in:
System falls asleep
System locks while waking up
Black screen with VGA readout at top left "113-A9902-108 RV570 BIOS 702m/581e"
Same result if energy saver puts computer to sleep. Went into bios and noticed following settings:
Vanderpool - disabled
XD bit - disabled
MPS - ver 1.1 (instead of 1.4)
Recall VGA BIOS from S3 - yes
After some tinkering I found that if Vanderpool is disabled and XD is enabled (or vice versa) the screen will turn off and computer will lockup when trying to sleep. The same thing happens when both Vanderpool and XD are enabled and MPS is set to 1.1.
I had slight success with this setting:
Vanderpool: enabled
XD: enabled
MPS version: 1.4
Recall VGA BIOS from S3: yes
The computer will sleep and wake with all USB devices functional, but the screen resumes at a very-low resolution (640x480 maybe?) and flashes between top left desktop and plain blue background. Mouse and keyboard work and I can run programs and attempt to switch screen resolutions, which blanks the screen for a moment but does not fix anything. Sometimes the flashes stop and the desktop disappears for no apparent reason, forcing me to hard reboot. Also, this phenomenon is not consistently reproducible. Sometimes the computer doesn't even go into sleep mode. But, if it does reach sleep the low-res flickering desktop thing happens at wake.
Finally I have a useable S3 with these settings:Vanderpool: Enabled
XD: Enabled
MPS version: 1.4
Recall VGA BIOS from S3: no
With those settings the computer will sleep and wake with all USB devices AND the desktop appears with the right resolution! All applications appear and I can drag and resize windows and use menus. Almost perfect except some windows apppear to not refresh correctly. For example, time counter on itunes is frozen while music plays. Also, menu items don't highlight in blue during mouseover. Killing Finder seems to fix these issues. Also also the fan on my X1950 Pro blows loudly after wake, just as it does when my computer first boots and before the card realizes it's not running hot. Finally after wake I can shut the computer off but if I try to restart it OSX closes everything up and hangs.
I think if I could re-initialize the graphics card after wake then everything would be perfect, but I don't know how to do that.
In any case, I hope some of this long and rambling account helps someone smarter than I to solve the sleep problem