i just wanted to add to this thread as it led me to a possible cause for other people who may also have a osx86 system that is locking up with a display in suspend, i didn't find the voodoo power management kexts in my system but I did find AppleGraphicsPowerManagement.kext and AppleIntelCPUPowerManagement.kext both of which I am guessing are irrelevant on my m3n78-em based hackintosh, one due to the cpu being AMD the other due to the fact i'm running an nvidia card some NVDANVxxHal's and the corresponding ResMan (and QE/CI and QuartzGL all running). So I have deleted them. fingers crossed I've nailed the issue, as I am writing this after implementing and before rebooting.

Running 10.5.7 also, incidentally. iAKTOS v7. if that helps.