In series 6 chipsets the MEI (Management Interface Engine) has device-id 0x1C3A but in series 7 chipsets it has device-id 0x1E3A so that the AppleIntelMEIDriver does not match the device and won't load, but without AppleIntelMEIDriver running AppleIntelHD3000Graphics.kext won't be able to recognize the Framebuffer, times out and unloads itself leaving you without graphics acceleration. Adding the correct device-id enables loading of the driver.
AppleIntelFramebufferCapri.kext needs a small plist edit. Both these edits are needed (for Sandy Bridge processor ONLY) because of the MEI driver device ID of the board not being Sandy Bridge friendly. Basically the system will try to load the AppleIntelFramebufferCapri.kext and not the AppleIntelSNBGraphicsFB.kext so the MEI driver device ID from the Capri kext needs to be taken from that kext and put into the AppleIntelSNBGraphicsFB.kext and you need to then either delete the Capri kext completely or modify the device ID in it so it does not load.