In my case, i just added this to my com.apple.boot.plist:
<key>Kernel Flags</key>
<string>arch=x86_64</string>
<key>PCIRootUID</key>
<string>1</string>
<key>GraphicsEnabler</key>
<string>Yes</string>
Do note, such a change will try to make your hack boot at 64 bit and if your system does not support this, it will most likely kill your hack.
You should try to test if you hack supports 64 bit.
At boot, press any key and use this:
arch=x86_64 and press enter.
If your system is capable of booting, it will just boot and you can add that to the mentioned file.
The next step is to restart and try the following at boot
PCIRootUID=1 GraphicsEnabler=Yes and press enter (if 1 does not produce any result, you can try 0)
Again, same thing, if it works, at least in Lion, it will load the correct framebuffer. And if it work, just add to the listed plist file.
Hope it works.