Article: MultiBeast 5.4 Update
A friend from work also runs a hackintosh on his GA-X58A-UD3R on which he also reinstalled 10.8.4 and then used Multibeast 5.4.0. The same issue with Sleep not working happened with him as well, whereas before it was working fine for him. He describes the monitor staying dark after attempting to wake his computer. Also just as in my case, he also needs to do a hard reboot to get out of this situation because the computer otherwise becomes completely non-responsive.
I told him I had the same problem and number of people had reported the same issue. I had found that it was specifically the Fakesmc.kext version 5.2.724 that is included with Multibeast 5.4.0 that was the cause of this problem which seems to break Sleep. I told him to delete Fakesmc.kext v5.2.724, and to install the previous Fakesmc.kext v5.1.61 which is included with Multibeast 5.3.1.
After replacing the newer Fakesmc.kext with the previous 5.1.61 version, to his surprise he found that normal Sleep functionality was fully restored and now works properly again on his computer.
I'm glad I found a workaround for this, but I wonder if this will cause any other issues by having an older version Fakesmc.kext with the newer kexts that 5.4.0 installs? So far for me, running my system with the older Fakesmc 5.1.61 along with newer kexts installed with Multibeast 5.4.0, I haven't encountered any problems at all and everything seems to working perfectly normally and smoothly for me.
If anyone else is encountering problems with sleep with the new Fakesmc.kext v5.2.724, please let us know what your experience is. On another note, I want to say I'm very pleased the new Chimera no longer has those " "unable to handle key" messages appear on boot. Great job and thanks so much!