Anyone still having shutdown reboot or sleep problems

I tried it after the fixes in the P35 Control Center didn't work. Uninstalled those, installed this and booted with -f. Still doesn't work for me. Picking "sleep" shuts down my system. Any secrets you care to share on how to make it work? I already have S3 enabled in my BIOS.

You can also try using VoodooPower.kext instead, it fixes all reboot/shutdown problems on my machine (sleep not tested), apart from the power saving features.

Tried VoodooPower as suggested. Didn't help. I could always shut down and reboot fine. I just can't sleep. Since I don't want this thing running 24/7 and hate having to boot up twice a day, I really wish there was a good sleep solution. Especially since a cold boot often fails and leaves me with a blank screen and mouse cursor instead of a login box. Hitting the reset button to reboot fixes that, but it's yet more delay.

There was some toggle in OS X power options to check, I forgot the exact name, something that is like the opposite of what you want to achieve (like "always turn off the computer before sleep"), but it worked for me IIRC.
Anyway I got a Gigabyte P35 before and it always got troubles sleeping (or waking up) if you were doing overclock, not sure if thats your case...

Are you referring to "Restart automatically after a power failure"? I found that over at Insanelymac and tried it. Not only did it not work, it gave me a hell of a scare. It disabled my boot drive, which also has about 700GB on a separate partition. The drive wouldn't even show up on Disk Utility. A cold boot finally re-enabled it. I guess Sleep is a lost cause for me.

At least that helped me fix the "black screen on every cold boot" problem. When the system couldn't find the boot drive, it went to another, which had only a bare iPC install on it. I noticed that boot had no such problem. I suspected the EFI string was causing it, so I hand-edited the string out and used NVDarwin. That fixed it while keeping Core Image and Quartz Extreme enabled.

Well that worked for me on my P35 board, but only when the CPU is not overclocked, if its overclocked it will never wake up anyway, I think many Gigabyte P35 board got the same troubles with overclocking and S3 sleep.

@TechSgtChenTried VoodooPower as suggested. Didn't help. I could always shut down and reboot fine. I just can't sleep. Since I don't want this thing running 24/7 and hate having to boot up twice a day, I really wish there was a good sleep solution. Especially since a cold boot often fails and leaves me with a blank screen and mouse cursor instead…

I hope you didn't try them both at the same time. If you're using VoodooPower, you can't use OpenHaltRestart at the same time.

No, I always removed one before installing the other and rebooted with -f. And no overclocking.

already download, then what do i do? i cant run that?

I'm starting to think it might be the USB kernel extensions. I know they've been problematic in 10.5.6. I just recently upgraded to 10.5.7. Should I try the hacked 10.5.5 USB kexts, or is that a bad idea with 10.5.7? There must be some reason my EP35-DS3R won't sleep. Other people have gotten theirs to do so.

Sleep works greath on my ga ep35 ds mobo with xxx 10.5.6 updated to 10.5.7, just having problems with shutdown some times.