DP3 installed over DP2 (which was installed over DP1). Only change necessary was to add AppleHDA kext from SL10.6.2 to get sound working (that change has been required ever since 10.6.3). Fakesmc, Nullcpu, ethernet and audio enabler kexts were added to S/L/E at DP1. Installing over does not change these kexts so the only tweek for DP3 is to reinstall the old AppleHDA kext.
which bootloader do you take? when i install the dp3 over my dp2 and restart then everything is unchanged. same build number etc. nothing happens after a restart