My particular card is a Sapphire Radeon HD 6870 1GB GDDR5, PCI-e, 256 bit, DVI-I, DVI-D, HDMI, displayPort (Product # 11179-09-20G). I have tried adding different strings to org.chameleon.Boot.plist before asking for help, but I couldn't even boot into ML, so I had to revert to the original...