I tried enabling Power Management for a while with the Framebuffer, but nothing seemed to work. I thought that perhaps, there were no physical sensors in my laptop. But it was only a few days ago that I realized that NullCPUPowerManagement.kext was being used, but not in /S/L/E, but rather hidden in /System/Library/Extensions/myHack.kext/Contents/PlugIns. I tried deleting it like you said, but apparently, I need it because, otherwise, I get a kernel panic caused by AppleIntelCPUPowerManagement.kext. I don't have a screenshot on me right now, but I'll try to get one. I am using an Intel Core i3 CPU, so it should work. Maybe I need AppleIntelCPUPowerManagement.kext patched? Any ideas?
Try using KernelPatcher.dylib module. It makes Core i work on HP laptops (like mine). You can find it in the Chameleon bootloader pkg.
I've just installed Mavericks on my PC with a P8Z68 Deluxe/Gen 3 motherboard. Everything was fine on Mountain Lion but on Mavericks I have the same problem. I can put my PC in sleep at the first time and it's 20 secs slower than on Mountain Lion but when I try to put my PC in sleep again the screen becomes black for 2 secs and then it returns to OS X.