If you experience CMOS checksum errors and CMOS resets on wake or reboot after installing OS X 10.8 Mountain Lion on your Hackintosh, you need to patch the AppleRTC.kext. Open your Terminal and follow these easy steps:

1. First backup the original kext:

mkdir ~/Desktop/BackupRTC
sudo cp -r /System/Library/Extensions/AppleRTC.kext ~/Desktop/BackupRTC/

2. Copy the original kext to your desktop for patching:

sudo cp -r /System/Library/Extensions/AppleRTC.kext ~/Desktop/

3. Patch it:

sudo perl -pi -e 's|\x75\x30\x89\xd8|\xeb\x30\x89\xd8|' ~/Desktop/AppleRTC.kext/Contents/MacOS/AppleRTC

4. Delete the original version:

sudo rm -rf /System/Library/Extensions/AppleRTC.kext

5. Copy the patched version in the place using Kext Wizard, rebuild the permissions and the system cache.
6. Reboot.